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

Savings and Credit Cooperative Societies (SCCs): A Panacea to Accessing Funds for Housing Development to Workers of Public Institutions in Nigeria

This paper assesses the impact of Savings and Credit Cooperative Societies (SCCS) as a panacea to providing funds for housing development to workers in Nigeria public service. The Institute of Agricultural Research (IAR) Ahmadu Bello University, Zaria-Nigeria was used as a case study for the research. Questionnaires were administered to 82 staff of the institution that belongs to the institute cooperative society (IAR Rangwame Multipurpose Cooperative Society (IRMCS)) and a separate designed questionnaire was given to 3 officials of the society. Descriptive analysis, chi-square test and cooperators satisfaction index (CSI) was used for analyzing the data collected. The findings from the analysis showed that 7(8.5%) of IRMCS members have bare lands, 11(13.4%) have their houses under construction and 5(6.1%) have completed their houses while the remaining 59 members did not benefited IRMCS housing loan. The CSI on each attribute of “interest rate”, “affordability”, “transaction cost”, “availability” and “collateral” for cooperative loan are greater than 4 (close to 5) except for “availability” which is close to 4 and the aggregated CSI for all attributes is 4.17 which is also close to 5 is very high compared to National Housing Fund (NHF) CSI’s on each attributes which are all less than 2.7 with an aggregated CSI of 2.5. Also, the cooperators range of dissatisfaction index (RDI) was determined and it was found that cooperative loan had the lowest (0.832) against NHF of 2.41 and this indicates that IRMCS members are well satisfied with cooperative loans compared to the NHF. The paper concludes that SCCS can be a viable instrument in impacting positively towards funding housing projects to workers of public institutions. Keywords: SCCS, Informal sources of finance, Housing, NHF, CSI, RD

Revisiting Politicide: State Annihilation in Israel/Palestine

State annihilation is a persistent concern in Israel/Palestine. While the specter of Israel’s destruction increasingly haunts Israeli public political debates, the actual materialization of Palestinian statehood seems to be permanently suspended, caught in an ever-protracted process of state-building. The current paper claims that to understand the unfolding of the discursive formations, as well as the spatial dimensions of conflict and control in Israel/Palestine, we should explicate the workings of the processes of politicide. Politicide, in this regard, denotes the eradication of the political existence of a group and sabotaging the turning of a community of people into a polity. This analysis suggests that the insistence that the State of Israel is under threat of extinction should be understood as a speech act, a performative reiteration, which allows for the securitization of Israeli rule in the occupied Palestinian territory, a securitization which then serves to rationalize the ongoing concrete politicide of the Palestinians. Elaborating on the concept of politicide, and diverging from defining it solely through the use of brute violence, this examination suggests that what is often overlooked in discussions of politicide are the seemingly more benign means of its implementation, the micro-power mechanisms of spatial control, prohibitions and regulations

Sustainable release of propranolol hydrochloride laden with biconjugated-ufasomes chitosan hydrogel attenuates cisplatin-induced sciatic nerve damage in in vitro/in vivo evaluation

Peripheral nerve injuries significantly impact patients’ quality of life and poor functional recovery. Chitosan–ufasomes (CTS–UFAs) exhibit biomimetic features, making them a viable choice for developing novel transdermal delivery for neural repair. This study aimed to investigate the role of CTS–UFAs loaded with the propranolol HCl (PRO) as a model drug in enhancing sciatica in cisplatin-induced sciatic nerve damage in rats. Hence, PRO–UFAs were primed, embedding either span 20 or 60 together with oleic acid and cholesterol using a thin-film hydration process based on full factorial design (2(4)). The influence of formulation factors on UFAs’ physicochemical characteristics and the optimum formulation selection were investigated using Design-Expert(®) software. Based on the optimal UFA formulation, PRO–CTS–UFAs were constructed and characterized using transmission electron microscopy, stability studies, and ex vivo permeation. In vivo trials on rats with a sciatic nerve injury tested the efficacy of PRO–CTS–UFA and PRO–UFA transdermal hydrogels, PRO solution, compared to normal rats. Additionally, oxidative stress and specific apoptotic biomarkers were assessed, supported by a sciatic nerve histopathological study. PRO–UFAs and PRO–CTS–UFAs disclosed entrapment efficiency of 82.72 ± 2.33% and 85.32 ± 2.65%, a particle size of 317.22 ± 6.43 and 336.12 ± 4.9 nm, ζ potential of −62.06 ± 0.07 and 65.24 ± 0.10 mV, and accumulatively released 70.95 ± 8.14% and 64.03 ± 1.9% PRO within 6 h, respectively. Moreover, PRO–CTS–UFAs significantly restored sciatic nerve structure, inhibited the cisplatin-dependent increase in peripheral myelin 22 gene expression and MDA levels, and further re-established sciatic nerve GSH and CAT content. Furthermore, they elicited MBP re-expression, BCL-2 mild expression, and inhibited TNF-α expression. Briefly, our findings proposed that CTS–UFAs are promising to enhance PRO transdermal delivery to manage sciatic nerve damage

Irreducible Locked Symphysis Pubis Disruption Caused by Incarcerated Urinary Bladder in a 14-year-Old Boy, a Case Report and Review of the Literature

Ali Fergany,1 Ahmed A Khalifa,2 Faisal A Mokhtar,3 Osama Farouk1 1Orthopaedic Department, Assiut University Trauma Hospital, Assiut, Egypt; 2Orthopaedic Department, Qena faculty of medicine and University Hospital at South Valley University, Qena, Egypt; 3Orthopedic Department, Faculty of Medicine for Boys at Al Azhar University, Cairo, EgyptCorrespondence: Ahmed A Khalifa, Email [email protected]: Urinary bladder entrapment or incarceration within pelvic fracture have been described in many reports in the literature, most of which were reported in adult patients. We describe a case of a 14-year-old boy presented with isolated locked symphysis pubis disruption after falling from a height. His initial evaluation was negative for any other associated injuries. The decision was made to treat him surgically by open reduction and internal fixation using a symphyseal plate; however, upon completing the Pfannenstiel incision, the surgeon faced a soft tissue mass hindering bony fragment dissection; upon careful examination, the soft tissue mass turned out to be entrapped urinary bladder within the symphyseal disruption. After careful soft tissue dissection, and with the help of Jungbluth distractor, the disruption was over-distracted, the bladder was freed entirely (which was intact) and reduced to its position, followed by the application of a symphyseal plate in a reduced symphysis pubis position. The patient did well postoperatively, and at three months follow up, the disruption and fracture united, and there were no urinary-related symptoms. Although rare, urinary bladder entrapment within an element of anterior pelvic fracture could be a reason for the difficult reduction; careful evaluation and steady soft tissue dissection are paramount for avoiding undue iatrogenic urinary bladder injury.Keywords: pediatric pelvic fracture, bladder entrapment, case repor

Performance Evaluation of Fiber-reinforced Ferroconcrete using Response Surface Methodology

Fibre-reinforced ferroconcrete is a new-generation type of concrete that has been found to have adequate performance. Global emissions of CO2 as a result of concrete production have damaged the earth's atmosphere. These emissions, together with construction waste, such as ceramic powder and aluminium waste, are considered one of the most harmful wastes to the environment, eventually leading to pollution. In this study, the fibre-reinforced ferroconcrete (FRFC) contained waste aluminium fibre, cement, ceramic waste powder, corrugated wire mesh, and fine and coarse aggregate. The cement content in the concrete mix was partially replaced with Ceramic Powder (CP) in proportions of 0%, 10%, and 20%, while the Aluminum Fibers (AF) were added in proportions 0, 1, and 2% to the concrete mix. The variation of ceramic powder and aluminium fibres was done using the central composite design of Response Surface Methodology (RSM) to create experimental design points meant to improve the fibre-reinforced ferroconcrete's mechanical performance. The results conclude that the mechanical performance of the FRFC was slightly improved more than conventional concrete, where at 20% replacement of ceramic powder and 1% addition of aluminium fibre to the concrete mix. There was more compressive, flexural, and split tensile strength increase than conventional concrete, with control concrete having strengths of 13.060, 5.720, and 3.110 N/mm2 and ferroconcrete 15.88, 6.68, and 3.83 N/mm2 respectively. This was further confirmed with microstructural images. The RSM model, with parameters such as; contour plots, analysis of variance, and optimisation, was used to effectively predict and optimise the responses of the ferroconcrete based on the independent variables (Aluminum fibre and Ceramic Powder) considered. The results of the predicted data show a straight-line linear progression as the coefficient of determination (R2) tends to 1, indicating that the RSM model is suitable for predicting the response of the variables on the FRFC. Doi: 10.28991/CEJ-2023-09-04-014 Full Text: PD

Polyorchidism: case report and literature review

Polyorchidism is a rare congenital anomaly frequently associated with maldescent testis, hernia, and torsion. Reports in the literature show an increased risk of testicular malignancy in the presence of polyorchidism. This entity has characteristic sonographic features and the diagnosis is often made on the basis of sonography. A conservative approach is the treatment of choice in uncomplicated cases. We report a male of 26-years old with 2 testicles in right side diagnosed by ultrasound. A brief history and review of the literature is also presente

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication