New simple equations for effective length factors

AbstractIn most current codes of design steel members and frames, specifications for the design of compression columns or of beam-column use the effective length factor; K. The effective length factor is employed to facilitate the design of framed members by transforming an end-restrained compressive member to an equivalent pinned-ended member. The effective length factor is obtained by solving the exact equations numerically which require many routine calculations or by using a pair of alignment charts for the two cases of braced frames and sway frames. The accuracy of these charts depends on the size of the chart and the reader’s sharpness of vision. Instead of using complicated equations or charts, simple equations are required to determine the effective length factor directly as a function of the rotational resistant at column ends (GA, GB). In this paper, new simple and accurate equations for effective length factors are presented using multiple regressions for tabulated exact values corresponding to different practical values of the rotational resistance at column ends (GA, GB). The investigated equations are more accurate than equations that are recommended in some steel constructions codes. Comparisons between the results of the present equations and those obtained by equations presented in previous researches with those obtained by exact solutions are also given in this paper

Influence of analysis and design models on minimum weight design

The results of numerical experiments designed to illustrate how the minimum weight design, accuracy, and cost can be influenced by: (1) refinement of the finite element analysis model and associated load path problems, and (2) refinement of the design variable linking model are examined. The numerical experiments range from simple structures where the modelling decisions are relatively obvious and less costly to the more complex structures where such decisions are less obvious and more costly. All numerical experiments used employ the dual formulation in ACCESS-3 computer program. Guidelines are suggested for creating analysis and design models that predict a minimum weight structure with greater accuracy and less cost. These guidelines can be useful in an interactive optimization environment and in the design of heuristic rules for the development of knowledge-based expert optimization systems

Appraisal of circulation routine duties in academic libraries

This paper examines the circulation services in the circulation department of academic libraries. It defines circulation services and identifies types of circulation routine duties. Specific mention was made of shelving of consulted books, shelving arrangement, shelf reading, registration of library users, charging system, brown system, discharging system, advantages and disadvantages of brown charging system, book reservation, keeping of reserved collection, circulation of reserved books, treatment of overdue, lost of books on loan and library statistics among other as duties perform in circulation department of libraries.Keywords: Library Service, Circulation Duties, Challenges, Academic Librarie

Adsorption of benzyldimethyldodecylammonium chloride onto stainless steel using the quartz crystal microbalance and the depletion methods: An optimisation study

The adsorption behaviour of benzyldimethyldodecylammonium chloride (C12BDMAC) corrosion inhibitor from aqueous solutions onto a stainless steel surface has been investigated using the quartz crystal microbalance (QCM) technique and the depletion-HPLC method. Three different experimental procedures were used to carry out the adsorption measurements using the QCM. The results revealed that the employed experimental procedure had a marked influence on both of the measured frequency and dissipation energy changes. Additionally, the measured changes in the normalized frequency and dissipation changes were found to be overtone-dependent. The adsorbed amounts determined by QCM were higher than those determined by depletion due to strong contributions from the bulk liquid properties. The direct application of the measured frequency shifts corresponding to the lowest dissipation changes, ?flowestD, in the Sauerbrey equation was effective in minimising these contributions within an acceptable experimental tolerance. A correction procedure, based on the Kanazawa equation, has been proposed and applied successfully to separate the contribution from the bulk effects to the calculated adsorbed mass. The adsorption isotherms obtained from the corrected frequency shifts and the depletion method were perfectly matched over the whole range of concentrations investigated

Comparison of Saudi child versus parent‑report of child tooth‑brushing practices

Objective: This cross‑sectional study compared Saudi children’s tooth‑brushing practices as reported by children and parents and then matched the agreement of reports.Materials and Methods: A sample of 100 Saudi parents and their children of ages 8–12 years participated in this cross‑sectional investigation. A self‑administered structured questionnaire regarding the current tooth‑brushing practice and habits at home was filled by the child. The same questionnaire was filled independently by parents.Results: Mothers were more likely to teach children about tooth‑brushing and fathers were minimally helping children during tooth‑brushing. Mothers were the first to teach the children and approximately 33% of the children started brushing their teeth by age 5. Children and parents reported that children clean their teeth using a tooth‑brush (73.74% and 76.77%), miswak (5.05% and 5.05%), or both (21.21% and 18.18%), respectively.Conclusions: There was some agreement between reported tooth‑brushing practice of children and their parents. It is important to question both the child and parent regarding oral hygiene practice and compare their answers to get more broad knowledge about their practices. Approximately, one‑third of the children started brushing their teeth by age 5, which differs from recommended oral hygiene practices.Keywords: Dental plaque, oral health education, oral hygiene, patient education, tooth‑brushin

Neutrosophic Crisp α-Topological Spaces

In this paper, a generalization of the neutrosophic topological space is presented. The basic definitions of the neutrosophic crisp α-topological space and the neutrosophic crisp α-compact space with some of their characterizations are deduced. Furthermore, we aim to construct a netrosophic crisp α-continuous function, with a study of a number its properties

Risk Factors Associated with Mild Cognitive Impairment аmong Apparently Healthy People and the Role of MicroRNAs

BACKGROUND: Mild cognitive impairment (MCI) is a stage between the expected cognitive decline of normal ageing and the serious decline of dementia. AIM: To identify risk factors and role of miRNAs associated with mild cognitive impairment (MCI) among employees. SUBJECTS AND METHOD: A cross-sectional study was carried out on 186 employees aged between 40 and 65 years. Cognitive function was evaluated using ACEIII, MoCA, and Quick cognitive tests. Medical history and lifestyle were assessed. Family 132 & 134 miRNA expressions were assessed by real-time PCR. RESULTS: MCI was detected among 14 / 186 (7.5%). miRNA 132 expression was the only significant miRNAs to detect MCI with low sensitivity and specificity (70%). The logistic analysis revealed that higher miRNA132 expressions, low monthly intake of; vegetables, unroasted nuts, low education and higher ALT levels were predicting factors for MCI with AOR 1.1 (1.01-3.3), 1.2 (1.04-1.43), 0.8 (0.8-0.98), 2.7 (1.9-7.4) and 1.6 (1.1-2.3) respectively. CONCLUSION: MiRNAs expression showed low sensitivity and specificity in detecting MCI; only miRNA 132 might be used. Several modifiable factors seem to reduce the risk of MCI

The autoimmune rheumatic diseases – an introduction

We have brought together opinion leaders to provide up to date reviews on common autoimmune rheumatic diseases with clinically relevant diagnostic and management strategies, as well as insightful updates on pathogenesis, classification and outcomes

Bipolar sealing devices versus endoscopic vascular staplers during laparoscopic splenectomy in children with benign hematological diseases

Background: Splenectomy, whether open or laparoscopic, is considered a step of management in many children with benign hematological diseases such as immune thrombocytopenia, thalassemia, autoimmune hemolytic anemia, and spherocytosis. The major challenge during laparoscopic splenectomy (LS) is the rich blood supply of the spleen. Many techniques were considered to control the vascular supply of the spleen. Staplers, clips, either titanium or hemoclips, a bipolar sealing device (BSD), or ultrasonic shears were all used to complete LS. We aimed to compare the results of using BSD versus endoscopic staplers for vascular control of the pedicle during LS.Patients and methods: The study was carried out on 30 children with benign hematological diseases who presented to the Pediatric Surgical Unit. They were grouped randomly into two groups: group A and group B. Group A included 15 patients who were subjected to LS in which BSD was used for vascular control, whereas group B included 15 patients subjected to LS in which endoscopic staplers were used for vascular control of the pedicle.Results: The mean age of the children in group A was 9.60 years, whereas the mean age of the children in group B was 10.40 years. In group A, the mean estimated amount of blood loss was 72.27 ml. However, this was 80.67ml in group B. In group A, the mean operative time required was 39.00 min, whereas it was 56.27 min in group B. The indications for splenectomy were thalassemia in 15 cases (seven for group A and eight for group B), idiopathic thrombocytopenic purpura in 13 cases (seven for group A and six for group B), and spherocytosis in two cases (one for each group). The mean splenic size in group A was 10.43 cm, whereas it was 11.73 cm in group B.Conclusion: LS has evolved over the last decade because of the advancements of BSDs and endoscopic staplers. According to our data the use of LigaSure reduces the overall operative time, operative blood loss, and associated complications compared with the use of staplers.Keywords: children, laparoscopic, splenectom