Theoretical and experimental investigation of thin-walled structural elements under various load actions

Thin-walled structural forms exhibit in their behaviour under compressive actions, features normally suppressed by the heavy section outlines used in hot rolled constructions. Thus, over-all instability under a combination of torsion and flexure, is obtained in a much wider range than in hot rolled sections; and local instability, i.e., buckling of the plate components (flange or web), disregarded in hot rolled construction becomes one of the chief characteristics of thin-walled behaviour. The subject-matter of the thesis deals with these two forms of instability both theoretically and experimentally. The contents of the thesis are divided into 4 main parts, each part being further subdivided into convenient sections. Part I presents a critical review of published work relevant to: (i) over-all instability in torsion-flexure, and (ii) local instability of plate components of struts in flexure. This reveals the absence of theoretical treatment of: (i) mixed boundary conditions in torsional-flexural buckling, e.g., a hinged end strut with warping restraint, and (ii) the determination of the critical stress in local buckling of plates subjected to linearly varying compressive load actions, applicable to the plate components of structural sections subjected to eccentric axial loading. There also appears to be a scarcity of experimental investigations in this latter field. The review is followed by the theoretical analysis presented in Part II. This develops an iterative method of general application to problems of instability. The method is first applied to the derivation of the torsional-flexural buckling load for mixed boundary conditions not hitherto solved, such as the combination of hinged ends with warping restraint. The second application of the iteration method is the derivation of the local buckling strength of plates elastically supported along one longitudinal edge and free along the other. The loading for these boundary conditions, not hitherto considered in published literature, is an axial compressive action linearly varying across the width of the plate. This is applied to assess the strength in local instability of eccentrically loaded thin-walled channel sections. The experimental work described in Part III presents the results of some 190 strut tests to destruction. These consisted of equal and unequal angle and channel specimens of 65 S.W.P. Aluminium Alloy, 3 inches to 132 inches long. The tests were designed to investigate the effects on over-all and local buckling of the variation of load eccentricity, length, section profile and method of manufacture (cold formed versus extruded). In Part IV the results obtained are analysed and compared with the theory showing good agreement. The textual part of the thesis concludes with a Summary which draws attention to the main features of instability conditions investigated, as indicated by the theory and confirmed by the experimental work. The thesis concludes with a Bibliography, followed by 7 Appendices in which the details of various aspects of the work are presented

Hope Global -- In Process Laser Cutter Blade Cleaning

Since 1883, Hope Global has been manufacturing and supplying various high quality and durable textiles to businesses and industries around the globe. Their most demanded product is the beaded profile which is used primarily in interior seat linings of trucks. [1] These are produced across four production lines and involves a 1000W laser cutter on each. In these laser cutters are configurations of aluminum blades that act as supports for the profiles running underneath the laser. When the laser makes its automated cuts, the polypropylene plastic of the beaded profile gets melted on to the blades. Over the course of continuous cutting, the melted plastic builds up these blades and becomes a problem. The current cleaning process of these blades involves the machine operator opening the laser cutter door which stops the laser from cutting. However, the profile is still fed through the line at 80 ft/min creating scrap. The time it takes the operator to clean each blade takes about two minutes per production line. The blades are usually cleaned two or three times per hour during a 21-hour work day, which, across four separate lines, creates huge amounts of scrap throughout the day. This immense amount of scrap causes significant material loss for Hope Global which means significant money lost. The scope of this project is to reduce the clean time of these blades as much as possible to reduce the scrap produced. Throughout the course of this semester, a design was formulated to help Hope Global with this problem. Extensive research was performed to generate ideas and explore similar design concepts and ideas. This search was two-fold; firstly, a scholarly literature search was performed, then a patent search. Unfortunately, because the laser cutter machine is custom built to fit Hope Global’s needs, there are no similar designs on the market today. Therefore, a bank of concepts was generated among group members and analyzed until a design concept was chosen for the foundation and continuation of the project. This concept was reviewed while considering the design specifications laid out later in this report, and continuously improved upon. After review, the design was constructed and proven to work in physical form. This provided evidence for an integral step in the design process, the proof of concept. After proving the basic design worked effectively, the process of optimizing the design began. Over the course of the Spring semester, the team prototyped and tested its proof of concept repeatedly. After numerous tests, it was determined a scraper design was more effective than a brush design. For the remainder of this semester, this scraper idea was applied to the prototype and optimized into the final product of the project. The design was proven to work very effectively and efficiently and was easy enough to operate by the machine operators to deem it as a viable and usable way to clean aluminum blade sin the laser cutter. Overall, the team’s work on this project was successful in completing the main objective from the beginning of the year

Duchenne Muscular Dystrophy (DMD) Diagnosis: Past and Present Perspectives

Duchenne muscular dystrophy (DMD) is a fatal X-linked disorder, characterized by progressive skeletal muscle wasting. The disease is caused by various types of mutations in the dystrophin gene (DMD). The disease occurs at a frequency of about 1 in 5000 male births, making it the most common severe neuro-muscular disease. In addition to clinical examinations of muscle strength and function, diagnosis of DMD usually involves a combination of immunological assays using muscle biopsies, typically immunohistochemistry and western blotting, and molecular techniques such as DMD gene sequencing or Multiplex Ligation Dependent Probe Amplification (MLPA) using blood samples. In fact, precise molecular diagnosis is a prerequisite for determining the appropriate personalized therapeutic approach such as exon-skipping, gene therapy or stem cell-based therapies in conjunction with gene editing techniques like CRISPR-Cas9. However, the quest for reliable biomarkers with high sensitivity and specificity for DMD from liquid biopsy is still a hotspot of research, as such non-invasive biomarker(s) would not only facilitate disease diagnosis but would also help in carrier detection, which will eventually result in better disease management. In this chapter, we will illustrate the detailed current and prospect strategies for disease

Evaluation of a thrice weekly administration of teicoplanin in the outpatient setting; retrospective observational multi-centre study

Introduction: The glycopeptide teicoplanin is commonly utilised to facilitate Outpatient Parenteral Antimicrobial Therapy (OPAT). Licensed for once daily maintenance dosing, teicoplanin’s long half-life allows for less frequent dosing (e.g. thrice weekly) following successful loading. This service evaluation reviews the safety and effectiveness of a novel thrice weekly teicoplanin dosing regimen. Methods A retrospective, observational study was conducted at Chelsea & Westminster hospital (March 2018 – July 2020), evaluating trough serum teicoplanin concentrations for patients receiving >5 days of teicoplanin in the OPAT setting. Teicoplanin dosing and administration (once daily versus thrice weekly), clinical outcomes, and therapeutic levels were analysed for all patients. The project was registered with clinical governance locally. Results A total of 82 patients treated with teicoplanin in the OPAT service where included; 53/82 receiving thrice weekly and 29/82 receiving once daily dosing. Mean teicoplanin trough levels were similar in both groups (26.2mg/L and 25.8mg/L in once daily and thrice weekly groups, p=0.8895). High clinical success rates were recorded in both groups (25/29 [86.2%] versus 50/53 [94.3%]). No correlation with clinical outcomes and initial teicoplanin serum levels was identified. Normal renal function (>90mL/min) was associated with lower teicoplanin serum concentrations (21.4mg/L[±10.1] versus 29.7mg/L[SD±14], p = 0.0178) in the thrice weekly dosed group but not with the once daily dosed group (mean 28.2mg/L[±9.4] versus 23.7mg/L[±9.9], p = 0.2201). Conclusions This study supports thrice weekly teicoplanin as a convenient and effective OPAT for administration in the OPAT setting. Therapeutic drug monitoring is advised to adjust for intra-patient variability

Duchenne Muscular Dystrophy (DMD) Treatment: Past and Present Perspectives

Duchenne muscular dystrophy (DMD) is one of the fatal X-linked disorders that are characterized by progressive muscle weakness and occur due to mutation in the largest human gene known as the DMD gene which encodes dystrophin protein that is mandatory for keeping the muscles structurally and functionally intact. The disease always affects boys (1 from every ~5000), and in some cases the female carriers are symptomatic. The disease usually leads to impairment in cardiac and pulmonary functions leading to the death of the patients in very young ages. Understanding DMD through precise molecular diagnosis will aid in determining the suitable therapeutic approach for the cases like designing exon-skipping antisense oligonucleotides (AOs) or stem cell-based therapies in conjunction with gene editing techniques (CRISPR/Cas9). Such therapies can correct the genetic defect in the DMD gene and ameliorate the symptoms. In this chapter, we will illustrate the past and current strategies for DMD disease treatment

IN VITRO EVALUATION OF ENSILING AND /OR EXOGENOUS FIBROLYTIC ENZYME SUPPLEMENTATION OF DATE PRESS CAKE

This study was conducted to evaluate the effect of ensiling and /or exogenous fibrolytic enzyme supplementation date press cake using in vitro batch culture technique . Untreated date press cake (DPC) and ensiled DPC with exogenous fibrolytic enzymes (ZAD1 and ZAD2) and with or without adding urea compared to corn grains were in vitro evaluated using batch culture technique. DM, NDF and ADF degradation and total gas production as well as fermentation parameters of the incubated samples were determined after 24 h of fermentation. Total VFAs, proportions are not affected (P > 0.05) by any of the treatments. However, value of ammonia concentration was higher (P 0.05) with the ensiling treatments. There were no significant differences in the values of DMD and OMD between the different treatments. But, the values of NDFD and ADFD were increased (P0.05) between the corn grain and the DPC without any treatments. While, values of metabolizable protein (MP) and efficiency of microbial biomass production (EMP) were increased (p<0.05) with DPC compared to corn grains . There was no significant difference in the rumen activity when using date press cake (DPC) or corn grains. Moreover, the ensiling process did not cause a clear improvement in rumen fermentation

GENETIC DIVERSITY ASSESSMENT OF IN VITRO IRRADIATED TOMATO (LYCOPERSICON ESCULENTUM MILL.) USING SCOT MARKERS

Tomato (Lycopersicon esculentum Mill.) is considered the major and important globally vegetable crops especially in Egypt. Tissue culture techniques have facilitated the induction of mutant which helps in crop improvement. The mutation induction in vegetative crops through tissue culture may be the optimal method to improve these crops. Tomato explants of Idkawy Egyptian cultivar were cultured in vitro on MS medium supplemented with 0.2 mg/L BAP. The resulted plantlets were irradiated with different gamma radiation doses (50, 100, 150, 200 or 250 Gy) and the survival and mean of shoot length decreased as gamma radiation doses increased. The survival percentages of irradiated plantlets were ranged from 78.75% with 50 Gy dose to 18.75% with 250 Gy dose, while the shoot length values were decreased by a rate of 2.71 cm for dose 50 Gy and 1.2 cm for 250 Gy dose. The ten SCoT primers amplified a total of 114 amplicons with a range from 4 with SCoT-4 primer to 18 amplicons with SCoT-5  primer with an average of 11.4 amplicons per primer, The radiation specific markers were ranged from one fragment with SCoT-1 and SCoT-2 primers, SCoT- 5 two fragments with primer to five fragments with SCoT-3 and SCoT-33 primers

Neonatal hyperbilirubinemia and Rhesus disease of the newborn: incidence and impairment estimates for 2010 at regional and global levels.

BACKGROUND: Rhesus (Rh) disease and extreme hyperbilirubinemia (EHB) result in neonatal mortality and long-term neurodevelopmental impairment, yet there are no estimates of their burden. METHODS: Systematic reviews and meta-analyses were undertaken of national prevalence, mortality, and kernicterus due to Rh disease and EHB. We applied a compartmental model to estimate neonatal survivors and impairment cases for 2010. RESULTS: Twenty-four million (18% of 134 million live births ≥ 32 wk gestational age from 184 countries; uncertainty range: 23-26 million) were at risk for neonatal hyperbilirubinemia-related adverse outcomes. Of these, 480,700 (0.36%) had either Rh disease (373,300; uncertainty range: 271,800-477,500) or developed EHB from other causes (107,400; uncertainty range: 57,000-131,000), with a 24% risk for death (114,100; uncertainty range: 59,700-172,000), 13% for kernicterus (75,400), and 11% for stillbirths. Three-quarters of mortality occurred in sub-Saharan Africa and South Asia. Kernicterus with Rh disease ranged from 38, 28, 28, and 25/100,000 live births for Eastern Europe/Central Asian, sub-Saharan African, South Asian, and Latin American regions, respectively. More than 83% of survivors with kernicterus had one or more impairments. CONCLUSION: Failure to prevent Rh sensitization and manage neonatal hyperbilirubinemia results in 114,100 avoidable neonatal deaths and many children grow up with disabilities. Proven solutions remain underused, especially in low-income countries