Bibliographies: '4 x 4 block schedule' – Grafiati (2024)

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Abstract Experimental sprays were applied to single-tree plots in a randomized block design consisting of 2 replicates of ‘Fuji’ and 2 replicates of ‘Golden Delicious’. Treated single trees were separated by others not sprayed with insecticides. The trees were 4 years old and planted to a spacing of 20 x 30 ft. All treatments were applied with a Myers Mity Mist sprayer calibrated to deliver 100 gpa, driven at 2.4 mph. The date of application for the treatments was 21 Jun. All plots received a regular fungicide maintenance schedule of Ziram 76WP. All maintenance materials were applied using the alternate row middle method of application. Effectiveness on the spirea aphid was evaluated by counting the number of aphid-infested leaves/10 actively growing shoots, and by rating the density of aphids/most infested leaf on a 0-4 scale as given in the table footnotes. The number of natural enemies preying on aphids was determined by counting the number observed in a 2-min examination around the periphery of each plot tree. Pest pressure was moderate during the course of the experiment.

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Roses in nursery and landscape settings are frequently damaged by black spot, whose causal agent is the fungus Diplocarpon rosae F.A. Wolf. Potassium silicate was assessed as a media-applied treatment for decreasing the severity and incidence of black spot infection. Roses were treated with 0, 50, 100, or 150 mg·L-1 silicon as potassium silicate incorporated into irrigation water on either a weekly or daily schedule. Five weeks after treatments were initiated, plants were inoculated with D. rosae. Roses began to show visual symptoms of infection §4 days later. Roses that had 150 mg·L-1 silicon applied on a daily schedule had significantly more silicon present in their leaves than other treatments as measured by scanning electron microscopy and energy-dispersive x-ray analysis. In addition, roses that had 100 and 150 mg·L-1 silicon applied on a daily schedule had fewer black spot lesions per leaf and fewer infected leaves than any of the other treatments by the end of the experiment 7 weeks later. Although roses treated with higher levels of silicon on a daily basis fared better than roses in the other treatments, all of the roses were heavily infected with D. rosae by the end of the study. The results reported here indicate that using potassium silicate in irrigation water may be a useful component of a disease management system.

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Abstract Experimental sprays were applied to replicated 3-tree plots in a block of ‘Bartlett’ (84%), ‘Bosc’ (9%), and ‘D’Anjou’ (7%) pears. Trees were planted at a spacing of 24 X 24 ft and were 16 years old. Each treatment was replicated 4 times in a randomized block design. Experimental sprays were applied with a Friend Airmaster ‘309’ calibrated to deliver 100 gpa at 2.2 mph. The first table contains a listing of the application dates. All plots received a regular fungicide maintenance schedule of Benlate 50DF, Streptomycin and Ziram 76WP. All sampling was conducted on the middle ‘Bartlett’ tree in each replicate. All treatments were evaluated by counting eggs and/or nymphs from leaf samples using a binocular microscope under 10 X magnification at 6-9 d intervals. Counts were made on 15 spur leaf samples from 1 May to 25 May, on 8 spur and 7 third most distal leaf samples from 1 Jun to 14 Jun, on 15 third most distal leaf samples on 22 Jun to 7 Jul. Adult PP were sampled by making 2 taps on 8 limbs per center plot tree. All adults dropping onto a 0.2 m2 collecting tray were counted. Russet evaluations were made on pear fruits (30 per replicate). Each replicate was rated as 0 (no russet), 1 (raised lenticels), 2 (1-10% russeted surface), 3 (11-25% russeted surface), 4 (26-50% russeted surface), or 5 (>51% russeted surface). The individual ratings were added to calculate a russet rating for each replicate. Possible ranges for the replicate russet ratings (and estimate of range of percent of surface russeted) are 0-30 (none to raised lenticels), 31-60 (raised lenticels to 1-10% russeted surface), 61-90 (1-10% to 11-25% russeted surface), 91-120 (11-25% to 26-50% russeted surface), and 121-150 (26-50% to >51% russeted surface).

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BackgroundAlthough the value of ultrasound-guided (USG) lumbar medial branch blocks (MBB) has previously been examined in several clinical trials, blocking the L5 dorsal ramus (DR) remains a technical challenge and we sought to examine the accuracy of a novel technique targeting this level.MethodsIn this prospective cohort study, 115 patients scheduled for an L4 MBB and L5 DR block underwent an ultrasound scan to assess their lower spine sonoanatomy. Subjects in whom the necessary landmarks could be visualized underwent a USG L5 DR block using a pivot technique, which involved redirecting a needle from its position on the L5 transverse process after an L4 MBB. Success was determined by a blinded observer who examined the contrast distribution on postprocedural X-ray images. In addition to the final needle position, performance time, the number of needle passes, and any complication were recorded.ResultsA total of 100 patients had a USG block and 15 patients (13%) were excluded because of poor landmark visibility. The latter group presented a significantly higher body mass index (38.90±7.50 vs 26.31±4.25 kg/m2, p=0.004). A total of five failures were noted (95% success rate), this included three patients with transitional anatomy in whom needles were placed at the wrong level and two cases of incomplete contrast coverage possibly related to the partial intravascular injection. Performance time was 153.93±41.56 s and the median number of needle passes was 2 (range 4). No significant complications were noted.ConclusionThe pivot technique provides a reliable approach for USG L5 DR ramus blocks.Trial registration numberNCT03805906

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Background Patients on chronic anticonvulsant drugs are relatively resistant to certain nondepolarizing neuromuscular blockers such as pancuronium, vecuronium, pipecuronium, doxacurium, or metocurine, but not resistant to mivacurium and atracurium. This study investigated the influence of chronic carbamazepine therapy on the neuromuscular block induced by the new muscle relaxant rocuronium. Methods Twenty-two otherwise healthy individuals scheduled for neurosurgical operations were studied: 11 of them were on chronic treatment with carbamazepine; the others served as control subjects. The median duration of carbamazepine therapy was 9 weeks (range, 4-312 weeks). After premedication with oral diazepam, anesthesia was induced with fentanyl and thiopental and maintained with nitrous oxide/oxygen and 0.5% inspired isoflurane. Rocuronium, 0.6 mg/kg (2 x ED95), was given for intubation. The ulnar nerve was stimulated, and the evoked electromyogram recorded using a Datex NMT monitor. Results Based on the response to the first of four stimuli, neither the lag time nor the onset-time differed between the two groups. However, the intervals of recovery to 10%, 25%, 50%, and 75% of the baseline response and the recovery index (RI, 25%-75%) were significantly shorter in patients on chronic carbamazepine therapy. Conclusions The authors conclude that the duration of the rocuronium-induced neuromuscular block is significantly shortened by preceding chronic carbamazepine therapy.

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Abstract Experimental sprays were applied to single-tree plots in a randomized block design consisting of 4 replicates of ‘Yorking’. Treated single trees were separated by others not sprayed with insecticides. The trees were 8 years old and planted at a spacing of 20 x 30 ft. All treatments were applied with a Myers Mity Mist sprayer calibrated to deliver 100 gpa driven at 2.4 mph. All plots recieved a regular fungicide maintenance schedule of Benlate 50DF, Dithane 75DF, Nova 40WP and Ziram 76WP and the insecticide Imidan 70WP. All maintenance materials were applied using the alternate row middle method of application. The effect of the sprays on WALH was evaluated by counting the number of nymphs/25 injured leaves/tree. Effectiveness on the spirea aphid was evaluated by counting the number of aphid-infested leaves/10 top terminals, and by rating the density of aphids/most infested leaf on 0-4 scale as explained in the table footnotes. The number of natural enemies of aphids was determined by counting the number observed on 10 growing shoots per tree. Effectiveness of the test chemicals on ERM was evaluated by counting the mites several times during the season on samples of 25 random leaves/tree, 100 leaves/treatment. The predator, S. punctum, was observed by making 3-min counts of adults and larvae around the periphery of the trees. STLM was evaluated by a 5-min count of tissue-feeding mines around the periphery of the trees at the end of the 1st and 2nd generations. Also, STLM parasitism was evaluated at the end of the second generation by collecting 25 random leaves/tree and dissecting the mines found. Pest pressure was moderate throughout the season.

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10563 Background: P inhibits activation of the Akt pathway which results in apoptosis and block cancer cell proliferation. Since AKT is a molecule downstream of Kit, its inhibition may overcome Kit-dependent imatinib resistance. We performed a phase II trial to assess antitumor activity of perifosine in patients with advanced GIST who were refractory to imatinib mesylate. Methods: Pts with Kit(+) advanced GIST who have PD on IM were eligible. Pts continued their current dose of IM and were randomized to one of two dosing schedules of P (Arm A: 100 mg p.o. qd x 28 + IM or Arm B: 900 mg [300 mg p.o tid] qweekly + qd IM). A Bayesian approach was utilized to assess a target response rate or 20% with an unacceptable toxicity rate of 15% or less. Response was measured at q8 wk intervals by RECIST and Choi criteria. The primary endpoint was to determine the efficacy of P with IM in pts with advanced GIST with PD while receiving IM. Results: From 8/2005 to 7/2008, 41 pts were accrued. After 1 pt exclusion and 2 cross-overs, 22 pts were in Arm A and 18 pts in Arm B. Median age was 58 (range, 32–82), 51% were male, and median ECOG PS was 1. The most common primary site of disease and metastasis was the stomach (29%) and liver (66%), respectively. KIT genotype was available for 22 pts(54%); 5(12%) WT, 13(32%) exon 11 mutations, and 4(10%) exon 9 mutations. The median number of cycles was 2 (range, 1–24). By Choi and RECIST, 30 pts(73%) and 36 pts(87%) were available for response, respectively. No CR was identified but the PR rate was 4/36 (11%) by Choi (4 PR, 9 SD) and 0/36 (0%) by RECIST (16 SD). 4/5 (80%) of pts with WT KIT appeared to benefit (Choi: 1 PR, 3 SD; RECIST: 4 SD). Median PFS and OS for 40 pts were 2.2 months and 18.3 months. No difference in PFS was noted for the 2 schedules. Toxicity was assessed in 39 pts; 46 grade 3 events and 4 grade 4 events (ALT elevation, blurred vision, fatigue, and mood alteration) were noted. The most common grade 3 event was fatigue (20%). Three pts (7%) were removed from the study for toxicity (Arm A:1 pt, Arm B:2 pts). Conclusions: The addition of P to IM has minimal activity in IM-refractory GIST although its activity in GIST with WT KIT may be further investigated. No significant financial relationships to disclose.

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Abstract Rationale: BET-bromodomain (BRD) proteins play a major role in the epigenetic regulation of gene transcription, notably of genes with superenhancer promoter regions including many oncogenes, such as MYC. OTX015 is a specific BRD 2, 3 and 4 inhibitor that blocks oncogene transcription, and triggers growth inhibition and apoptosis in acute leukemia cell lines and patient cells in vitro (Braun et al. ASH Annual Meeting 2013). Based on these findings, a Phase 1 study of OTX015 was designed for patients with advanced acute leukemia. Patients & Methods: Patients with various unselected relapsed/refractory leukemia subtypes for which no standard therapy options were available were enrolled in this ongoing Phase 1 study. Patients aged < 60 years had to have failed at least two lines of therapy and those aged >60 years at least one line. At least 5% bone marrow leukemic blasts were required at study entry. OTX015 was given orally, daily for 14 days of 21-day cycles (cy). The dose was escalated from 10 to 160 mg daily (QD) according to a standard 3+3 dose-escalation design, to determine the maximum tolerated dose (MTD) or biologically optimal dose. A BID schedule was tested at dose level (DL) 4 (40 mg x 2) and a continuous schedule at 120 mg. Pharmacokinetics was studied on day 1 and residual concentrations were measured on days 2, 8 and 15. Responses were assessed on blood and bone marrow aspirations at baseline, days 8, 22 and 43. Blasts at baseline and day 8 were stored for pharmacodynamic biomarker evaluation. Cytogenetic and molecular markers were collected based on center practice. Results: From January 2013 to June 2014, 36 patients were treated over 6 dose levels: 33 with acute myeloid leukemia (AML), 2 with acute lymphoblastic leukemia and 1 with refractory anemia with excess blasts. Median age was 70 years (range 19-85), 20 patients were male, 29 patients had ECOG 0-1, and 16 AML patients had normal karyotype. Patients had a median of 2 prior therapy lines (range 1-4). The median number of OTX015 cycles administered was 2 (range 1-14+), including 9 patients with >3 cycles. Among the 28 patients evaluable for dose limiting toxicity (DLT), no DLTs were observed through DL5 (120 mg QD). The MTD was exceeded at DL6 (160 mg QD) with one patient experiencing grade 3 diarrhea and another grade 3 fatigue and anorexia. The main toxicities were non-cumulative grade 1-2 gastrointestinal events (6 patients diarrhea, 3 dysgueusia, 3 abdominal pain, 3 nausea, 1 anorexia), hyperglycemia (3 patients), coagulation factor VII decrease (6 patients) and direct bilirubin increase (3 patients) (two latter AEs asymptomatic). These toxicities were mainly observed at QD doses above 80 mg and with 40 mg BID. Dose proportional plasma concentrations were observed and trough concentrations > 500 nM (in vitro active concentrations) were regularly observed from 80 mg/day. Clinically relevant activity was reported in 5 AML patients treated at 10, 40 and 80 mg, including one sustained CR from cy 4 to cy 12 (40 mg QD) and one CR with incomplete platelet recovery (CRp) from cy 2 to cy 5 (80 mg QD). Two patients (10 mg QD, 40 mg QD) had partial blast clearance (disappearance of peripheral blasts and decrease >50% in bone marrow blast percentage) and the remaining patient (40 mg BID) had gum hypertrophy resolution. Four of these 5 patients had secondary or therapy-related AML, 4 had normal karyotype and 2 had an NPM1 gene mutation. Conclusions: OTX015 single agent exhibits antileukemic activity over a wide range of DLs and plasma concentrations in patients with advanced AML. MTD is exceeded at 160 mg QD. The safe recommended dose and schedule is close to being identified. Central extensive molecular marker analysis is being performed and will be prospectively implemented in an expansion cohort. Updated data will be presented and will include correlations between regimen, pharmacokinetics, clinical activity and molecular profile. Table Dose (Schedule) N pts evaluable Evidence of activity DLT 10 QD (14/21) 3 1 20 QD (14/21) 3 40 QD(14/21) 4 1 (CR) 80 QD(14/21) 3 2 (1 CRp) 40 BID (14/21) 6 1 120 QD (14/21) 3 120 QD (21/21) 3 160 QD (14/21) 3 Diarrhea (1) Anorexia/fatigue (1) Disclosures Dombret: Oncoethix SA: Research Funding. Preudhomme:Oncoethix SA: Research Funding. Berthon:Oncoethix SA: Research Funding. Raffoux:Oncoethix SA: Research Funding. Thomas:Oncoethix SA: Research Funding. Vey:Oncoethix SA: Research Funding. Gomez-Roca:Oncoethix SA: Research Funding. Ethell:Oncoethix SA: Research Funding. Yee:Oncoethix SA: Research Funding. Bourdel:Oncoethix SA: Employee of study CRO Other. Herait:Oncoethix SA: CMO and Shareholder Other. Michallet:Oncoethix SA: Research Funding. Recher:Oncoethix SA: Research Funding. Roumier:Oncoethix SA: Research Funding. Quesnel:Oncoethix SA: Research Funding.

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Background Continuous passive motion after major knee surgery optimizes the functional prognosis but causes severe pain. The authors tested the hypothesis that postoperative analgesic techniques influence surgical outcome and the duration of convalescence. Methods Before standardized general anesthesia, 56 adult scheduled for major knee surgery were randomly assigned to one of three groups, each to receive a different postoperative analgesic technique for 72 h: continuous epidural infusion, continuous femoral block, or intravenous patient-controlled morphine (dose, 1 mg; lockout interval, 7 min; maximum dose, 30 mg/4 h). The first two techniques were performed using a solution of 1% lidocaine, 0.03 mg/ml morphine, and 2 microg/ml clonidine administered at 0.1 ml x kg(-1) x h(-1). Pain was assessed at rest and during continuous passive motion using a visual analog scale. The early postoperative maximal amplitude of knee flexion was measured during continuous passive motion at 24 h and 48 h and compared with the target levels prescribed by the surgeon. To evaluate functional outcome, the maximal amplitudes were measured again on postoperative day 5, at hospital discharge (day 7), and at 1- and 3-month follow-up examinations. When the patients left the surgical ward, they were admitted to a rehabilitation center, where their length of stay depended on prospectively determined discharge criteria Results The continuous epidural infusion and continuous femoral block groups showed significantly lower visual analog scale scores at rest and during continuous passive motion compared with the patient-controlled morphine group. The early postoperative knee mobilization levels in both continuous epidural infusion and continuous femoral block groups were significantly closer to the target levels prescribed by the surgeon than in the patient-controlled morphine group. On postoperative day 7, these values were 90 degrees (60-100 degrees)(median and 25th-75th percentiles) in the continuous epidural infusion group, 90 degrees (60-100 degrees) in the continuous femoral block group, and 80 degrees (60-100 degrees) in the patient-controlled morphine group (P &lt; 0.05). The durations of stay in the rehabilitation center were significantly shorter: 37 days (range, 30-45 days) in the continuous epidural infusion group, 40 days (range, 31-60 days) in the continuous femoral block group, and 50 days (range, 30-80 days) in the patient-controlled morphine group (P &lt; 0.05). Side effects were encountered more frequently in the continuous epidural infusion group. Conclusion Regional analgesic techniques improve early rehabilitation after major knee surgery by effectively controlling pain during continuous passive motion, thereby hastening convalescence.

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BackgroundThe clinical effectiveness of intermittent montelukast for wheeze in young children is unclear. Previous work has been equivocal. Variation in copy numbers of the specificity protein 1-binding motif in the arachidonate 5-lipoxygenase (ALOX5) gene promoter; where the wild type has five copies per allele, denoted here as 5/5, but variant genotypes may have 1–8 copies on each allele, denoted as x/x or 5/x, influences montelukast efficacy in asthmatic adults. This polymorphism may identify a responsive subgroup within this population.ObjectivesTo assess the clinical effectiveness of montelukast in preschool wheezing children. To explore the effect of theALOX5promoter genotype on this effect.DesignA multicentre, parallel-group, double-blind, randomised, placebo-controlled trial.SettingTwenty-one primary care sites and 41 secondary care sites in England and Scotland.ParticipantsChildren aged 10 months to 5 years with two or more wheeze episodes, one within the last 3 months, stratified byALOX5promoter genotype, either 5/5 or [5/x + x/x]. Children with other respiratory vulnerabilities were excluded.InterventionParent-initiated 4 mg oral granules of montelukast or identical placebo administered once daily for 10 days from the onset of every cold or wheeze episode over 12 months.Main outcome measureNeed for unscheduled medical attendance for wheezing.RandomisationChildren were stratified byALOX5promoter genotype, either 5/5 or [5/x + x/x], where x ≠ 5. Children in each stratum were independently randomised to receive montelukast or placebo in a 1 : 1 ratio via a permuted block schedule (size 10). Clinical investigators and parents were blinded to treatment group and genotype stratum.MethodsGenotype was identified by analysis of salivary deoxyribonucleic acid. Analysis was by intention to treat. Primary outcome data came from treatment diaries, scheduled telephone calls and caregiver records.ResultsA total of 1358 children were randomised to receive montelukast (n = 669) or placebo (n = 677). Consent was withdrawn for 12 (1%) children. Primary outcome data were available for 1308 (96%) children. There was no difference in unscheduled medical attendances for wheezing episodes between children in the montelukast and placebo groups {mean 2.0 [standard deviation (SD) 2.6] vs. mean 2.3 (SD 2.7) unscheduled medical attendances; incidence rate ratio (IRR) 0.88, 95% confidence interval (CI) 0.77 to 1.01;p = 0.06}. Compared with placebo, unscheduled medical attendances for wheezing episodes were reduced in children given montelukast in the 5/5 stratum [mean 2.0 (SD 2.7) vs. mean 2.4 (SD 3.0) unscheduled medical attendances; IRR 0.80, 95% CI 0.68 to 0.95;p = 0.01], but not in those in the [5/x + x/x] stratum [mean 2.0 (SD 2.5) vs. mean 2.0 (SD 2.3) unscheduled medical attendances; IRR 1.03, 95% CI 0.83 to 1.29;p = 0.79,p-interaction = 0.08]. We recorded one serious adverse event: a skin reaction in a child allocated to placebo.InterpretationThere is no clear benefit of intermittent montelukast in young children with wheeze. However, the 5/5ALOX5promoter genotype might identify a montelukast-responsive subgroup.LimitationsThe study lacks power to confirm the validity of the suggested genotype stratum effect. Additionally, the effect is contrary to that hypothesised and is not supported by urinary data. We could not robustly measure treatment compliance.Future workFuture work should test the stratum effect with a repeat trial in the apparently more responsive (5/5) stratum only.Study registrationClinicalTrials.gov NCT01142505.FundingThis project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership.

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The primary purpose of this research was to investigate how science teachers engaged students under the 4 x 4 block schedule and how the teachersâ understanding of how they used instructional strategies influenced their lessons. As an inquiry-based approach has been adopted by the National Science Standards, research has suggested that block scheduling provides more time for teachers to incorporate varied teaching strategies such as inquiry-based teaching. This research investigated the questions: What instructional strategies do science teachers use to engage students on the 4 x 4 block schedule? How do science teachers understand their use of instructional strategies? The methodology was qualitative in nature and involved a multiple case study of three high school science teachers at a large rural county high school. Data sources included pre-observation interviews, classroom observations, post-observation interviews, and the collection of documents and artifacts such as lesson plans, student hand-outs, worksheets, laboratory exercises, homework and other document(s) the teacher used to prepare for or implement a lesson. The evidence observed in this study, suggests that the strategies used by these three science teachers remain mostly didactic in nature. Although the teachers reported in the interview phase that they use a wide variety of strategies, what was observed within the 4 x 4 block structure was the use of didactic strategies, not different strategies. Although the teachers were aware of more holistic strategies, such as inquiry-based and cooperative learning, they were not adopted nor adapted within the lesson. The three teachers used strategies that were consistent with their scientific realist views concerning the nature of science. These scientific realist philosophies are antithetical to a social constructivist approach to teaching and learning, which is what the National Research Council suggests science teachers adopt.
Ed. D.

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The research investigated whether 4 x 4 block scheduling had any effect on students' achievement in Advanced Placement Calculus AB and described some of the dynamics involved in the shifts to 4 x 4 plans. Data from 52 schools (38 North Carolina, 14 Virginia) were divided into two groups: (Sample 1) 25 schools in which the course was taught in one semester (N = 252) and (Sample 2) 27 schools in which it was taught in two semesters (N = 355). Using two-tailed Z and chi square goodness-of-fit tests {dollar}(\alpha=0.05),{dollar} the 1995 AP test mean score of each sample was compared to the mean of the 103,032 students who took the test. The z test showed that Sample 1 made significantly lower scores. The effect size ({dollar}-{dollar}0.51) and chi square test supported this conclusion. The chi square test revealed significantly higher scores for Sample 2, but the z test did not. The study also found that schools used diverse practices regarding both AP classes and the change process. The study has implications for instruction, staff development, and administrative decision-making related to block scheduling.

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Thesis (Ph. D.)--Illinois State University, 2003.
Title from title page screen, viewed October 19, 2005. Dissertation Committee: Edward R. Hines (chair), Darryl A. Pifer, Albert T. Azinger, Norman Durflinger. Includes bibliographical references (leaves 107-112) and abstract. Also available in print.

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Thesis (Ed. D.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains xiii, 135 p. Includes abstract. Includes bibliographical references (p. 109-118).

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The primary purpose of this study was to examine whether attendance, academic achievement, school climate, student stress, and teacher burnout improved in an inner city, predominantly African American high school after the implementation of a 4 x 4 block schedule. Data concerning student academic achievement and absenteeism in 14 classrooms were gathered from the school's Annual Scholastic Reports. Data concerning the instructional practices of eight teachers were gathered through the teacher version of the Instructional Practices Survey and compared to a student version of the Instructional Practices Survey to determine whether student perception of instructional practices coincided with the teachers' perceptions. Classroom climate was examined by administering the Classroom Environment Survey to seven teachers and 130 of their students. Student stress levels were examined from the results of the School Situation Survey returned by 106 students. The Maslach Burnout Inventory was used to gather data concerning the burnout levels of 13 teachers. This study found that increases in grade point average and decreases in absenteeism were not achieved after three years of block scheduling. Instructional practices of the teachers involved in this study did not change significantly. School climate, student stress levels, and teacher burnout were found to be in the average range.

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The main objective of this thesis is to examine the trade-offs between security and efficiency within symmetric ciphers. This includes the influence that block ciphers have on the new generation of word-based stream ciphers. By incorporating block-cipher like components into their designs, word-based stream ciphers have experienced hundreds-fold improvement in speed over bit-based stream ciphers, without any observable security degradation. The thesis also emphasizes the importance of keying issues in block and stream ciphers, showing that by reusing components of the principal cipher algorithm in the keying algorithm, security can be enhanced without loss of key-agility or expanding footprint in software memory. Firstly, modern block ciphers from four recent cipher competitions are surveyed and categorized according to criteria that includes the high-level structure of the block cipher, the method in which non-linearity is instilled into each round, and the strength of the key schedule. In assessing the last criterion, a classification by Carter [45] is adopted and modified to improve its consistency. The classification is used to demonstrate that the key schedule of the Advanced Encryption Standard (AES) [62] is surprisingly flimsy for a national standard. The claim is supported with statistical evidence that shows the key schedule suffers from bit leakage and lacks sufficient diffusion. The thesis contains a replacement key schedule that reuses components from the cipher algorithm, leveraging existing analysis to improve security, and reducing the cipher's implementation footprint while maintaining key agility. The key schedule is analyzed from the perspective of an efficiency-security tradeoff, showing that the new schedule rectifies an imbalance towards e±ciency present in the original. The thesis contains a discussion of the evolution of stream ciphers, focusing on the migration from bit-based to word-based stream ciphers, from which follows a commensurate improvement in design flexibility and software performance. It examines the influence that block ciphers, and in particular the AES, have had upon the development of word-based stream ciphers. The thesis includes a concise literature review of recent styles of cryptanalytic attack upon stream ciphers. Also, claims are refuted that one prominent word-based stream cipher, RC4, suffers from a bias in the first byte of each keystream. The thesis presents a divide and conquer attack against Alpha1, an irregularly clocked bit-based stream cipher with a 128-bit state. The dominating aspect of the divide and conquer attack is a correlation attack on the longest register. The internal state of the remaining registers is determined by utilizing biases in the clocking taps and launching a guess and determine attack. The overall complexity of the attack is 261 operations with text requirements of 35,000 bits and memory requirements of 2 29.8 bits. MUGI is a 64-bit word-based cipher with a large Non-linear Feedback Shift Register (NLFSR) and an additional non-linear state. In standard benchmarks, MUGI appears to su®er from poor key agility because it is implemented on an architecture for which it is not designed, and because its NLFSR is too large relative to the size of its master key. An unusual feature of its key initialization algorithm is described. A variant of MUGI, entitled MUGI-M, is proposed to enhance key agility, ostensibly without any loss of security. The thesis presents a new word-based stream cipher called Dragon. This cipher uses a large internal NLFSR in conjunction with a non-linear filter to produce 64 bits of keystream in one round. The non-linear filter looks very much like the round function of a typical modern block cipher. Dragon has a native word size of 32 bits, and uses very simple operations, including addition, exclusive-or and s-boxes. Together these ensure high performance on modern day processors such as the Intel Pentium family. Finally, a set of guidelines is provided for designing and implementing symmetric ciphers on modern processors, using the Intel Pentium 4 as a case study. Particular attention is given to understanding the architecture of the processor, including features such as its register set and size, the throughput and latencies of its instruction set, and the memory layouts and speeds. General optimization rules are given, including how to choose fast primitives for use within the cipher. The thesis describes design decisions that were made for the Dragon cipher with respect to implementation on the Intel Pentium 4. Block Ciphers, Word-based Stream Ciphers, Cipher Design, Cipher Implementa- tion, -

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From the retrospective analysis of correlation between the activity of tissue factor (TFA) of leukemia cells (LC) and DIC complication in patients with acute leukemia, we have already reported an adequate dose schedule of heparin treatment for DIC can be calculated in accordance with the TFA of LC To evaluate this dose schedule, the prospective analysis was designed. Prior to the remission induction chemotherapy, TFA of LC obtained from 67 patients with leukemia (ANLL: M1;5, M2;22, M;34, M4;8, M5;4, M6;3, CML-BC: 11) was measured by Nemerson's two-stage method reported previously. Regardless of DIC complication, continuous heaprin therapy with 0, 15,000 or 9,700X + 9,000 units/day (X: logarithm value of TFA) was started with chemotherapy in patinet with 0, 0.8−4.1 U or >4.1 U of TFA, respectively. The complete remission and significant decrease of LC were achieved in 16 patients with ANLL and 5 patients with CML-BC, respectively. In 20 patients whose LC had 0.8 U of TFA or more (group A), 15 and 1 patients were complicated by DIC before and after start of the chmotherapy, respectively. DIC was improved in all of these patients. Other 4 patients were not complicated by DIC. There was no major bleeding due to heparin administration. In 47 patients whose LC had less than 0.8 U of TFA (group B), 40 patients were not complicated by DIC throughout the observation period. Remaining 4 and 3 patients were complicated by DIC before and after start of the chemotherapy, respectively. Among these patients, only one, whose DIC was due primarily to endotoxinemia, failed in control of the DIC. Consequently, in 67 patients subjected to this study, only one patient died of complicated DIC, although 17 patients (group A:4, group B:13) died of various causes other than DIC during the observation periods. These results suggest that our dose schedule of heparin is appropriate for both prevention and treatment of DIC complication in leukemia patients.

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In the framework of the hydrogen flakes issue concerning the reactor pressure vessels of the two Belgian NPP’s Doel 3 and Tihange 2, the Federal Agency of Nuclear Control required to perform tests on large scale specimens taken from a block representative of the pressure vessels with the double objective of validating the structural integrity approach and of verifying the load capacity of the specimens affected by flakes. The large scale tests were led on many kinds of specimens: 4 points bending specimens, CT specimens and tensile specimens containing hydrogen flakes or flawed with EDM notches. All of these tests have been simulated using extend finite element method (XFEM). The paper describes the linear elastic and elastic-plastic fracture mechanics calculations performed in the frame of these large scale tests using XFEM and presents the comparison between simulations and experiments. A focus is done on the XFEM capabilities to model 3D complex shaped flaws like hydrogen flakes.

Abstract:

UK very high integrity (VHI) component classification includes design, manufacturing, and inspection requirements that go beyond those established in ASME BPVC Sec. III Subsection NB [1]. One of these requirements is to ensure the component is tolerant of manufacturing defects. This can be demonstrated using a Defect Tolerance Assessment (DTA) based on two parameters fracture mechanics method. The brittle fracture parameter of this assessment requires the analysis of stress occurring in the component against the plane strain fracture toughness, KIC of the material. This work focuses on the practical determination of KIC for materials chosen for a Boiling Water Reactor (BWR) Main Steam Piping (MSP) and Main Steam Isolation Valve (MSIV), which carbon steel seamless pipe SA-106 Grade C and carbon steel casting SA-216 Grade WCB, are respectively. These materials are usually tested by Charpy impact testing specified in [1], but there are not many studies reporting their KIC, and there is not enough information concerning actual piping and valve materials. Thus the authors implemented fracture toughness testing using J-resistance curve according to ASTM E 1820 [2] for test pipe and test casting block simulating actual MS Piping and MSIV, and evaluated KIC(J) to be used in DTA. KIC(J) is evaluated from elastic-plastic fracture toughness, JIC, gained from the J-resistance curve, and equivalent to KIC [3]. KIC(J) corresponds to KJIc in ASTM E 1820. There were some cases, however, in which valid JIC values could not obtained, because of the materials high toughness, test specimen size limitations, and uneven final crack sizes. When valid JIC can’t be obtained, retesting or remanufacturing would significantly affect plant construction schedule. Hence, alternative evaluation methods by which JIC can certainly be obtained are desired. In this study, the authors focused on two types of alternative JIC evaluation methods. The first one is the Stretch Zone Width (SZW) method, in which JIC is calculated from SZW measurements of crack tip plastic blunting on fracture toughness test specimens. The SZW method was well studied in the 1970s, and experimental data showed a clear correlation between JIC values obtained from J-resistance curves and JIC values obtained from SZW measurements [4]. The second method is by correlation of JIC with the energy absorbed during Charpy testing. As represented by Rolf’s study [5], it has been reported that there are correlations between Charpy absorbed energy and KIC for high tensile strength steels. In this study, the validity of the SZW method was first evaluated by comparing its results with JIC obtained from J-resistance curves. Then, the applicability of the JIC values to DTA of actual products was discussed. Finally, by comparing Charpy absorbed energy and KIC(J), the validity and applicability of KIC determination method with Charpy absorbed energy was discussed.

Abstract:

Abstract Since the field test of polymer flooding technology was carried out in the Bohai Oilfield in 2003, problems such as plugging of polymer-response wells have become increasingly worse, and conventional acidizing and plugging removal measures have had poor results. Therefore, this paper carries out research to provide a basis for effective plug removal in oil wells, to improve the productivity of polymer flooding oil wells. In this paper, the component analysis of the plug samples from the benefit injection wells in the field was carried out. The clogging mechanism was studied through X-ray diffraction, scanning electron microscopy, energy spectrum analysis, infrared spectroscopy, and chromatography, as well as through dynamic simulation evaluation of plugs and dynamic displacement experiments of long cores. Through simulation experiments, the clogging mechanism is clarified and the blockage radius range was obtained by various methods such as inverse effect of comprehensive measures, well test interpretation, and empirical formula calculation. The analysis results of the plugs show that the inorganic components of the plugs are calcium and magnesium carbonate scales, clay minerals and iron salt precipitation, and the organic components are the micelles formed by the crosslinking of trivalent metal ions. The greater the concentration of polymer produced, the greater the strength of calcium-magnesium scale aggregates and aluminum-iron-colloid elastomer, the greater the degree and depth of reservoir pore throat clogging, the larger the screen clogging area, which will even block the inlet of electric submersible pump. This will result in poor acidizing plugging effect and rapid decline in oil well productivity. Through various methods such as the inverse effect of comprehensive measures, well test interpretation, and empirical formula calculation, the blockage radius of polymer flooding response wells is greater than 4 meters. Based on this understanding, in the five wells plug removal measures, the unblocking radius and unblocking chemical agent system were adjusted and optimized. On-site application effect tracking shows that the plug removal measures have achieved good oil incremental effects, and the measures are all effective. Through the classification and comparison of oil well productivity characteristics, formation water composition, output polymer properties and other characteristics, this paper established the identification mark of plugging of polymer-response wells. In addition, an analysis method for clogging was established to clarify the composition and formation mechanism of the clogging. Finally, the plug radius calculation method was established by means of backstepping the effects of plug removal measures and well test interpretation analysis.

Abstract:

The high temperature composites have been studied for applications to secondary structures due to their light weight and thermal resistance. Relatively few studies have been conducted to consider them for primary structural load bearing capabilities. These studies focused on titanium matrix composites to characterize their material behavior [1], unidirectional [2], simple loading conditions [3, 4] in a laboratory environment or unrealistic structural geometry [5]. The purpose of this work was to study fatigue damage and determine fatigue life in titanium matrix composite panels at unloaded fastener holes subjected to thermo-mechanical fatigue loads with variable amplitudes and temperature ranges. The test panels were machined from a prefabricated structural component with pre-drilled fastener holes. The test material was a 32 ply, quasi-isotropic, approximately .224 inch thick titanium matrix laminated composite with SCS-6 fibers and Ti-15-3 metal matrix. The material was HIP consolidated followed by slow cool to room temperature. The thermal zone area was 2 inches long along specimen length and 1.875 inch wide with a .3125 inch fastener hole at the center of the thermal zone. All specimens were machined using a 3-D water jet cutter. The test system consisted of a closed loop servo-hydraulic 30 Kip test system equipped with an MTS model 458 control system, a 486 PC containing a Keithley Metrabyte DAS 1601 computer card. The specimens were gripped using MTS model 647 side load hydraulic wedge grips equipped with surfalloy grip surface. The thermal loads were provided by an Ameritherm 5 kilowatt induction power supply and a total temperature instrumentation model MC-125 temperature controller. The temperature controller was equipped with analog set point and recorder output of temperatures with both set for 1–5 volt signal levels for 0 to 1832 F. The computer generated the temperature and load profiles and monitored error band for temperature. The computer system was set to null pace the temperature and loads if the temperature exceeded a 18 degree F variation. In effect all processes would hold until the temperature error returned inside the error band. This temperature error control was accomplished by comparing the command signal to the temperature controller to the process temperature signal from the temperature controller. The nominal uniform temperature zone was one inch long centered at the specimen geometric center and maintained required temperatures within 10 degrees. The variations in temperatures along the crack line were controlled to with in 5 degrees. Cooling blocks were attached to the test samples at the end of uniform sections near the fillet blend. These blocks were cooled with water passages and compressed air was passed through holes in the blocks and impinged on the samples to provide additional cooling at the end of the thermal ramp during cool -down. The air was turned on by the computer at about 400 degrees F during each block. On all notched test samples, an extensometer was mounted across the center flaw to obtain load-deflection data (COD). The optical crack lenth measurements were made using a 20 X Gaertner traveling microscope. The load versus crack mouth opening displacement readings were taken to compare with the optical measurements of the crack length. The thermomechanical load spectrum was developed from the distribution and frequency of loading that the airframe will experience based on the design service life and typical design usage. The loads and environmental spectra are used to develop design flight by flight stress environment spectra. The data and failure surfaces were analyzed to study the high stress and low stress failure, environmental degradations, surface cracks in matrix and the effect of notch on crack initiation failure mechanism. During this investigation it was observed that the most difficult task in thermomechanical fatigue testing is to control the cooling rate as required by the thermal profile. The results show that the fatigue life depend on the applied maximum stress, increased temperatures and hold levels of both the loads and the temperatures. The variation in experimental fatigue life is with in the order of magnitude typical of fatigue data considering the complexity of the test and loading conditions. The SEM photographs and micrographs showed that in titanium matrix composite, the mode of cracking is under partial bridging of fibers at the matrix crack. The COD data was of little use for totally automated measurements when comparing with the crack sizes measured.