Effect of Load Condition on Turning Performance of a VLCC in Adverse Weather Conditions

Zaky, Mochammad,Yasukawa, Hironori Korean Society of Ocean Engineers 2018 Journal of advanced research in ocean engineering Vol.4 No.2

The load condition significantly influences ship maneuverability in calm water. In this research, the effect of the load condition on turning performance of a very large crude oil carrier (VLCC) sailing in adverse weather conditions is investigated by an MMG-based maneuvering simulation method. The relative drift direction of the ship in turning to the wave direction is $20^{\circ}-30^{\circ}$ in ballast load condition (NB) and full load condition (DF) with a rudder angle $35^{\circ}$ and almost constant for any wind (wave) directions. The drifting displacement in turning under NB becomes larger than that under DF at the same environmental condition. Advance $A_d$ and tactical diameter $D_t$ become significantly small with an increasing Beaufort scale in head wind and waves when approaching, although $A_d$ and $D_t$ are almost constant in following wind and waves. In beam wind and waves, the tendency depends on the plus and minus of the rudder angle.

Dental Panoramic Radiographic Indices as a Predictor of Osteoporosis in Postmenopausal Saudi Women

Ayman Zaky Elsamanoudy,Madiha Mahmoud Gomaa,Rabab Mohammed Feteih,Najlaa Mohammed AlAmoudi,Ayman Zaky Elsamanoudy,Mohammed Ahmed Hassanien,Mohammed-Salleh M. Ardawi 대한골대사학회 2018 대한골대사학회지 Vol.25 No.3

Background: Many oral presentations of osteoporosis-a bone metabolic disease-were recorded. Thus, we aimed to assess panoramic radiomorphometric indices with bone mineral density (BMD) values among Saudi postmenopausal women and its importance in the prediction of osteoporosis. Methods: A total of 431 Saudi women were enrolled in this study. Panoramic radiographs were obtained at the time of BMD measurement. Subjects were fatherly classified into; normal BMD, osteopenia, and osteoporosis groups. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), 25-hydroxy-vitamin D (25[OH]D) and intact-parathyroid hormone were measured. Moreover, serum creatinine, calcium, and phosphate, together with serum osteocalcin (s-OC), procollagen type I N-terminal propeptide (s-PINP) and cross-linked C-terminal telopeptide of type 1 collagen (s-CTX) were measured. Receiver-operator curve (ROC) curve analysis for use of mandibular cortical width (MCW), panoramic mandibular index (PMI), and maxillary-mandibular ratio (M/M ratio) to differentiate women with osteoporosis or osteopenia from normal subjects was calculated. Cut off values of 4.6 at T score <-1 and 4.1 at T score ≤-2.5 were used. Results: Body mass index is significantly low in the osteoporotic group. There is no significant difference in serum levels of LH, E2, calcium, phosphate, and 25(OH)D between the studied groups. Moreover, s-OC, C-terminal propeptide of procollagen type I, s-PINP, s-CTX, and urinary-CTX are significantly higher in osteoporosis than normal and osteopenia groups. ROC curve analysis revealed that MCW and PMI showed significant data while M/M ratio is non-significant. Conclusions: It could be concluded that MCW as an important panoramic radiographic parameter can be used for prediction and diagnosis of osteoporosis in postmenopausal Saudi women with low BMD.

The Effectiveness of a Tangible Game-based Learning on Kindergarten Children

Shazwina Zaky Binti Nublan Zak,Il-Yang Hong 한국콘텐츠학회 2017 한국콘텐츠학회 ICCC 논문집 Vol.2017 No.12

Corporate Social Responsibility, Profitability and Firm Value: Evidence from Indonesia

MACHMUDDAH, Zaky,SARI, Dian Wulan,UTOMO, St. Dwiarso Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.9

The intention of this research is to identify the effect of corporate social responsibility (CSR) disclosure on firm value with profitability as a moderating variable. Data collection is carried out with data documentation that is based on financial reports and sustainability reports. All companies listed on the Indonesia Stock Exchange (IDX) during the 2013-2017 period are considered as the population of this study. Samples were selected using the purposive sampling method. The following are criteria that would be used in this study: 1) publish a sustainability report using the GRI G4 standard as a reference in preparing reports for 2013-2016, 2) publish a complete financial report for the 2014-2017 observation period, 3) not experience a loss during the 2014-2017 period. The total sample of the study was 109 companies. The study uses path analysis assisted with WarpPLS software version 6.0. The results show that the disclosure of corporate social responsibility has a positive and significant effect on firm value, and profitability moderates the effect of corporate social responsibility disclosure on firm value. The implication of the research is that implementing corporate social responsibility is very important to increase firm's value and firm's sustainability in the future.

Float Like a Butterfly, Sting Like a Bee

Shazwina Zaky Binti Nublan Zak 한국콘텐츠학회 2015 ICCC International Digital Design Invitation Exhib Vol.2015 No.12

Synthesis, characterization, surface and biocidal effect of some germinate nonionic surfactants

Mohamed F. Zaky,Ismail A. Aiad,AHMED SALAH MAHMOUD TAWFIK 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Different fatty acid namely; palmitic, stearic, oleic and linoleic acids and polyethylene glycol-600 werereacted to give nonionic surfactants. The formed nonionic surfactants were reacted with germaniumdioxide in presence of sodium carbonate to form germinates nonionic surfactants (I, II, III, and IV). Thechemical structures of the synthesized surfactants were characterized by FT-IR and 1H-NMR spectra. Thesynthesized surfactants showed higher surface activity at different temperature and surface parametersinfluenced by chemical structure of surfactants. The thermodynamic calculations showed thatadsorption and micellization processes are spontaneous. The synthesized surfactants showed goodantimicrobial activities against the tested microorganisms including Gram positive, Gram negative aswell as fungi. The promising inhibition efficiency of these compounds against the sulfate reducingbacteria facilitates them to be applicable in the petroleum field as new categories of sulfate reducingbacteria biocides.

Comparative evaluation among various robust estimation methods in deformation analysis

Khaled Mohamed Zaky Hassan 대한공간정보학회 2016 Spatial Information Research Vol.24 No.4

There is different robust estimation methods used for detecting small gross errors which may be presence in geodetic observations. Some of these methods are robust M-estimators, Least Absolute Sum and Danish method. The conventional Least Squares Estimation method and these robust estimation methods have been tested and applied on a precise geodetic network designed for detecting earth’s crustal deformations using singlepoint and rigid body displacement models. The results show that, the method of least squares leads to biased, unfavorable solution and useless estimates if the singlepoint displacement does not taken into considerations in the solution’s mathematical model. In contrast, the results of robust estimation methods are attained unbiased in a single estimation step. A reliable separation of single-point displacement and the general deformation model is achieved without difficulties. The comparison of results proved that, the Danish method gave the most accurate results. It also was more sensitive to outliers which may be presence in surveying observations in case of applying single-point displacement model. The Least Absolute Sum method was very nicely reproduces the simulated deformations and does not show a contamination of the estimated positions of stable points in the case of rigid body displacement model. The results of adjustment using rigid body displacement model were not identical with the nearly correct results of single-point displacement model. So, the rigid body displacement model may be not suitable for geodetic networks.

A New Isolation and Evaluation Method for Marine-Derived Yeast spp. with Potential Applications in Industrial Biotechnology

( Abdelrahman Saleh Zaky ),( Darren Greetham ),( Edward J. Louis ),( Greg A. Tucker ),( Chenyu Du ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.11

Yeasts that are present in marine environments have evolved to survive hostile environments that are characterized by high exogenous salt content, high concentrations of inhibitory compounds, and low soluble carbon and nitrogen levels. Therefore, yeasts isolated from marine environments could have interesting characteristics for industrial applications. However, the application of marine yeast in research or industry is currently very limited owing to the lack of a suitable isolation method. Current methods for isolation suffer from fungal interference and/or low number of yeast isolates. In this paper, an efficient and non-laborious isolation method has been developed and successfully isolated large numbers of yeasts without bacterial or fungal growth. The new method includes a three-cycle enrichment step followed by an isolation step and a confirmation step. Using this method, 116 marine yeast strains were isolated from 14 marine samples collected in the UK, Egypt, and the USA. These strains were further evaluated for the utilization of fermentable sugars (glucose, xylose, mannitol, and galactose) using a phenotypic microarray assay. Seventeen strains with higher sugar utilization capacity than the reference terrestrial yeast Saccharomyces cerevisiae NCYC 2592 were selected for identification by sequencing of the ITS and D1/D2 domains. These strains belonged to six species: S. cerevisiae, Candida tropicalis, Candida viswanathii, Wickerhamomyces anomalus, Candida glabrata, and Pichia kudriavzevii. The ability of these strains for improved sugar utilization using seawater-based media was confirmed and, therefore, they could potentially be utilized in fermentations using marine biomass in seawater media, particularly for the production of bioethanol and other biochemical products.

Possible Anticancer Activity of Rosuvastatine, Doxazosin, Repaglinide and Oxcarbazepin

El Sharkawi, Fathia Zaky,El Shemy, Hany Abdelaziz,Khaled, Hussein Moustafa Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: Rosuvastatine, doxazosin, repaglinide and oxcarbazepin are therapeutic drugs available in the market for the treatment of different diseases. Potential to display antitumor activities has also been suggested. The aim of the current study was to evaluate their in vitro effects on some human transformed cell lines. Materials and Methods: Cytotoxicity of the four drugs was tested in MCF-7, HeLa and HepG2 cells by the neutral red assay method and also the effect of rosuvastatine and doxazosin against Ehrlich Ascities Carcinoma Cells (EACC) by trypan blue assay. Results: Rosuvastatine exerted the greatest cytotoxic effect against HepG2 cells with an $IC_{50}$ value of $58.7{\pm}69.3$; in contrast doxazosin showed least activity with $IC_{50}=104.4{\pm}115.7$. Repaglinide inhibited the growth of both HepG2 and HeLa cells with $IC_{50}$ values of $87.6{\pm}117.5$ and $89.3{\pm}119.5$, respectively. Oxcarbazepine showed a potent cytotoxicity against both HeLa ($IC_{50}=19.4{\pm}43.9$) and MCF7 cancer cells (($IC_{50}=22{\pm}35.7$).On the other hand the growth of EACC was completely inhibited by doxazosine (100% inhibition) while rosuvastatine had weak inhibitory activity (11.6%). Conclusions: The four tested drugs may have cytotoxic effects against hepatic, breast and cervical carcinoma cells; also doxazosine may inhibit the growth of endometrial cancer cells. Further investigations in animals are needed to confirm these results.

Pyridoxine supplementation during oocyte maturation improves the development and quality of bovine preimplantation embryos

Aboelenain, Mansour,Balboula, Ahmed Zaky,Kawahara, Manabu,El-Monem Montaser, Abd,Zaabel, Samy Moawad,Kim, Sung-Woo,Nagano, Masashi,Takahashi, Masashi Elsevier 2017 Theriogenology Vol.91 No.-

<P><B>Abstract</B></P> <P>Recently, inhibition of cathepsin B (CTSB) activity during <I>in vitro</I> maturation (IVM) and culture (IVC) improved the developmental competence and quality of bovine oocytes and embryos. E-64 is a widely used inhibitor to inhibit CTSB activity, however, E-64 inhibits not only CTSB activity but also the activities of other proteases including cathepsin L (CTSL), papain, calpain, and trypsin. Pyridoxine, the catalytically active form of vitamin B6, plays a crucial role in several cellular processes and has the ability to inhibit CTSB activity. However, whether pyridoxine has an improving effect during IVM of bovine oocytes is still unknown. In this study, we investigated the effect of pyridoxine supplementation during IVM on the developmental competence of bovine oocytes and the quality of the produced blastocysts. Supplementation of pyridoxine to the maturation medium significantly decreased the activity of CTSB in both bovine cumulus cells and oocytes. Moreover, pyridoxine improved both the blastocyst and hatched blastocyst rates. In addition, the presence of pyridoxine during IVM also significantly improved the quality of the produced embryos by increasing the total cell number as well as decreasing the CTSB mRNA expression and apoptotic rate. These results indicate that pyridoxine is a promising tool to improve the developmental competence of bovine oocytes and subsequent embryo quality.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We investigated the effect of pyridoxine during IVM on the developmental competence of bovine oocytes. </LI> <LI> Supplementation of pyridoxine during IVM significantly decreased the activity of CTSB in bovine COCs. </LI> <LI> Pyridoxine improved the developmental competence of bovine oocytes by increasing the blastocyst rate. </LI> <LI> Pyridoxine improved the quality of the produced embryos by increasing the TCN and decreasing the apoptotic rate. </LI> <LI> Therefore, pyridoxine is a promising tool to improve the developmental competence of bovine oocytes and embryo quality. </LI> </UL> </P>