Solving fractional programming problems based on swarm intelligence

This paper presents a new approach to solve Fractional Programming Problems (FPPs) based on two different Swarm Intelligence (SI) algorithms. The two algorithms are: Particle Swarm Optimization, and Firefly Algorithm. The two algorithms are tested using several FPP benchmark examples and two selected industrial applications. The test aims to prove the capability of the SI algorithms to solve any type of FPPs. The solution results employing the SI algorithms are compared with a number of exact and metaheuristic solution methods used for handling FPPs. Swarm Intelligence can be denoted as an effective technique for solving linear or nonlinear, nondifferentiable fractional objective functions. Problems with an optimal solution at a finite point and an unbounded constraint set, can be solved using the proposed approach. Numerical examples are given to show the feasibility, effectiveness, and robustness of the proposed algorithm. The results obtained using the two SI algorithms revealed the superiority of the proposed technique among others in computational time. A better accuracy was remarkably observed in the solution results of the industrial application problems

Diabetes Mellitus Prevalence and Burden Among Community Acquired Pneumonia Patients

This work aimed at measuring the prevalence of Diabetes Mellitus among community acquired pneumonia (CAP) patients and declaring its effect on CAP patient\u27s outcome. Both community acquired pneumonia and diabetes mellitus are common in Egypt, and patients with associated CAP and DM need special care and supervision. This prospective study was carried out on 108 CAP patients admitted to Abassia Chest Hospital during the period from January 2016 to December 2016. Clinical and radiological diagnosis of pneumonia and DM diagnosis were performed. DM recorded a prevalence of 39.8% among community acquired pneumonia patients. Disturbed level of consciousness is more frequent among diabetic patients than non diabetics. Diabetic patients recorded higher rate of hospital admission, longer duration of hospital stay, higher rate of ICU admission and more sever pneumonia than among non diabetic patients. CURB-65 score showed significant positive correlation with HbA1c of the patients. Associated community-acquired pneumonia and diabetes mellitus is frequent in our locality and labor a double burden on the affected patients leading to poorer prognosis, higher rate of hospitalization with longer duration of hospital stay and ICU admission. So CAP patients with DM need intimate care

Electrical performance study of a large area multicrystalline silicon solar cell using a current shunt and a micropotentiometer

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell by using multimeters suffer from some problems because the cell has high current intensity with low output voltage. So, the solar cell short circuit current values are obtained by measuring the voltage developed across a known resistance Current Shunt. Samples of the obtained current values are accurately calibrated by using a Micropotentiometer (μpot) thermal element (TE) to validate this new measuring technique. Moreover, the solar cell open circuit voltage has been measured. Besides, the cell output power has been calculated and can be correlated with the measured incident radiation

Stemness and osteogenic differentiation of induced pluripotent stem cells generated in xeno-free conditions

Mesenkymale stamceller (MSC) har lenge vært grunnleggende i strategiene for bein tissue engineering, og er viktige i dannelsen av nytt bein. Samtidig har disse cellene flere utfordringer som gjør grundig undersøkelse ganske vanskelig. MSC-lignende celler (iMSC) frembrakt fra induserte pluripotente stamceller (iPS) har dukket opp som levedyktige alternativer til tradisjonelle MSC. Som litteraturen viser, kan iMSC dannes fra ulike typer iPS, det vil si iPS generert fra forskjellige kilder. Men; siden celleomprogrammering generelt er en tidkrevende og ineffektiv prosess, er det viktig å finne kilder av celler som er mer mottakelige for denne omdannelsen. Videre, med tanke på translasjon, bør iMSC dannes ved hjelp av xeno-frie metoder som er i samsvar med GMP-retningslinjer. Dette inkluderer isolasjon og ekspansjon av den opprinnelige cellekilden, generering og dyrking av iPS, og differensiering av iPS til iMSC. Fokuset i denne avhandlingen var derfor å utvikle en xeno-fri protokoll for å generere iMSC og deretter å vurdere iMSC sin osteogene kapasitet. I den første studien var målet å vurdere og sammenligne den osteogene potensialet til BM-MSC som ble dyrket opp i to separate xeno-frie protokoller (grunnleggende medier supplert med enten platelet lysat (PL) eller humant AB-serum). Begge xeno-frie protokollene støttet BM-MSC ekspansjon in vitro og støttet også deres osteogene differensiering både in vitro og in vivo. Til slutt ble PL valgt som det xeno-frie tillegget for de gjenværende studiene på grunn av forskjellige faktorer, inkludert, men ikke begrenset til, praktisk anvendelighet, tilgjengelighet og fremtidig anvendelighet. Den andre studien hadde som mål å lage iPS fra forskjellige donor-like fibroblastkilder (dermale, buccale og gingivale) ved hjelp av en xeno-fri, PL-basert protokoll. De genererete xeno-frie iPS ble siden sammenlignet med xenogene iPS (FBS-protokoll) fra de samme donor-matchede fibroblastene. Begge protokollene støttet generering av iPS fra de ulike fibroblastene, men fibroblastene dyrket i PL viste generelt lavere omprogrammeringseffektivitet. Videre viste munn-fibroblastene seg generelt å være vanskeligere å omprogrammere enn dermale fibroblaster. Ved vellykket generering forble iPS geno/fenotype i stor grad uberørt av både ekspansjonsbetingelsene og den opprinnelige cellekilden. Målet med den tredje studien var å differensiere de genererte xenogenene og xeno-frie iPS til iMSC, og å vurdere og sammenligne deres osteogene potensial. Begge protokollene støttet differensiering av iPS til iMSC. Videre støttet protokollene osteogen differensiering av iMSC både in vitro og in vivo. Til slutt hadde den opprinnelige cellekilden liten innvirkning på den endelige iMSC geno/fenotype og osteogene potensial. Denne avhandlingen har sett på fordelene og utfordringene som oppstår når man utleder iPS/iMSC fra ulike kilder under xeno-frie forhold. Samlet sett viser disse funnene vei for videre evaluering og undersøkelse.Mesenchymal stem cells (MSC) have long been a cornerstone in bone tissue engineering strategies, catalyzing the formation of new bone. Nevertheless, these cells generally present with challenges making adequate investigation quite difficult. MSC-like cells (iMSC) generated from induced pluripotent stem cells (iPS) have emerged as viable alternatives to traditional MSC. As the literature has shown, iMSC can be generated from different types of iPS, i.e., iPS generated from different sources. However, since cell reprogramming is generally a tedious and inefficient process, it is vital to determine sources which are more susceptible to this procedure. Furthermore, for the purpose of translation, iMSC should be generated using xeno-free methods that are compliant with GMP guidelines. These include the isolation and expansion of the initial cell source, the generation and culture of the iPS, and the differentiation of iPS to iMSC. Hence, the focus of this thesis was to ultimately develop a xeno-free protocol for generating iMSC and to subsequently assess their osteogenic capacity. In the first study, the objective was to assess and compare the osteogenic potential of BM-MSC propagated in two separate xeno-free protocols (basal media supplemented with either platelet lysate (PL) or human AB serum). Both xeno-free protocols supported BM-MSC expansion in vitro while also supporting their osteogenic differentiation in both in vitro and in vivo settings. Eventually PL was selected as the xeno-free supplement of choice for the remaining studies due to a variety of factors including, but not limited to, practicality, availability, and future applicability. The second study aimed to generate iPS from different donor-matched fibroblast sources (dermal, buccal, and gingival) using a xeno-free, PL-based protocol. The generated xeno-free iPS were then compared to xenogenic iPS (FBS protocol) obtained from the same donor-matched fibroblasts. Both protocols supported the generation of iPS from the various fibroblasts, however, the fibroblasts propagated in PL showed generally lower reprogramming efficiencies. Furthermore, the oral fibroblasts generally proved to be more difficult to reprogram than the dermal fibroblasts. Upon successful generation, the iPS geno/phenotype remained largely unaffected by both the expansion conditions and initial cell source. The aim of the third study was to differentiate the generated xenogenic and xeno-free iPS into iMSC, and to assess and compare their osteogenic potential. Both protocols supported the differentiation of iPS into iMSC. Furthermore, the protocols supported the osteogenic differentiation of iMSC in both in vitro and in vivo settings. Finally, the initial cell source had little bearing on the eventual iMSC geno/phenotype and osteogenic potential. In the course of this thesis, we shed light on the advantages and hurdles encountered when deriving iPS/iMSC from various origins in xeno-free conditions. Collectively, these findings warrant further evaluation and investigation.Doktorgradsavhandlin

Prioritizing Safety Climate Improvements in the Indonesian Construction Industry Using Supervised Classification

Despite its significance, the Indonesian construction industry has poor safety performance. Improving the safety climate has been seen as a way to improve safety in the industry. Research on safety climate in this context has identified a range of safety climate factors that require improvements. However, construction organizations face difficulties in implementing improvement recommendations due to resource constraints. In order to help construction organizations in their efforts to improve the safety climate, this research demonstrates the use of supervised classification approaches to identify specific safety climate factors that construction organizations should focus on. Data were collected from 311 construction practitioners in Indonesia using a 22-item safety climate survey. Supervised classification methods, comprising ensemble methods, Support Vector Machine, Naive Bayes, and Nearest Neighbor, were used. The analysis identified 14 safety climate items that can represent the original dataset with high accuracy (93%). These 14 items can be considered crucial items that should be prioritized in the Indonesian construction industry. These items revealed that, due to the high power distance culture in Indonesia, top-down approaches, such as giving clear instructions, providing training, and reminding people often about safety, are effective for engaging employees to focus on and participate in safety. The findings also suggest that understanding cultural context is important to determine effective strategies to improve safety. This research has also demonstrated the potential application of supervised classification approaches to help decision makers improve safety by focusing on crucial factors within a context

Self-Consistent Random Phase Approximation - Application to the Hubbard Model for finite number of sites

Within the 1D Hubbard model linear closed chains with various numbers of sites are considered in Self Consistent Random Phase Approximation (SCRPA). Excellent results with a minimal numerical effort are obtained for 2+4n sites cases, confirming earlier results with this theory for other models. However, the 4n sites cases need further considerations. SCRPA solves the two sites problem exactly. It therefore contains the two electrons and high density Fermi gas limits correctly.Comment: 17 pages, 17 figure

THERMO-PHYSICAL PROPERTIES OF LIGHT WEIGHT EPOXY FOAMED BY SILOXANE BLOWING AGENT

The purpose of this study is to investigate the direct effect of using a blowing agent of siloxane (1, 1, 3, 3-tetramethydisiloxane) on the thermo-physical properties of the foamed epoxy. These properties are: density, glass-transition temperature, thermal conductivity and thermal expansion. The work has been conducted experimentally by manufacturing several specimens with different siloxane contents as: 0, 5, 10, 15 and 20 wt%. The properties of the specimens have tested under suitable conditions using different reliable instruments: differential scanning calorimetry, Lee-discs apparatus, and push rod dilatometer. Scanning electron microscope was used as well to analysis the morphological characteristics of the epoxy with respect to the pores generated by the blowing agent. In general, the foamed epoxy has shown different sizes of pores and extra crosslinking which leads to increase the glass-transition temperature of the material. Results show that the addition of 20% siloxane to the neat epoxy (as maximum) leads to: decreasing by 50% in bulk density, increasing by 20% in glass-transition temperature, decreasing by 30% in thermal conductivity, and decreasing by 75% in thermal expansion.                                             

Impact of Water Injection System on Diesel Engine Brake Power and Exhaust Emissions

A series of experiments were carried out to study and clarify the effect of Water Injection system (WI) on diesel engine performance and exhaust gas emissions (Nitrogen Oxides, Sulfur Dioxide, and Carbon Monoxide). The results obtained showed that, water injection increases the power output of the engine. Adding water to the incoming air allows for greater charge density. The water absorbs a large amount of heat as it vaporizes, thus reducing peak temperature and Nitrogen Oxides (NOX) emissions. WI also decreases the emissions of Sulfur Dioxide (SO2); the presence of water converts some of SO2 gas into sulfuric acid (H2SO4). Similarly, WI system was found to decrease the emissions of Carbon Monoxide (CO)