bluuebunny/crossref_metadata_2025 huggingface dataset:
Are temporomandibular disorders associated with facial asymmetry? A systematic review and meta‐analysis
Authors: Marques Fernanda Blaudt Carvalho , de Lima Lílian Siqueira , Oliveira Pedro Lima Emmerich , Magno Marcela Baraúna , Ferreira Daniele Masterson Tavares P. , de Castro Amanda Cunha Regal , Maciel Jose Vinicius Bolognesi , Ruellas Antonio Carlos de Oliveira , Maia Lucianne Copple
Published: July 2020

Objective

To assess scientific evidence of the association between temporomandibular joint (TMJ) disorders and facial asymmetry (FA).

Methods

A systematic review was performed in accordance with the PRISMA checklist. A search strategy was developed in electronic databases including MEDLINE, Scopus, Web of Science, Virtual Health Library and Cochrane Library until January 2020. Eligibility criteria included observational studies that investigated the occurrence of FA among patients with and without signs and symptoms of TMJ disorders. Risk of bias of individual studies was analysed after study selection and data collection processes according to Fowkes and Fulton guidelines. Four meta‐analyses (MA) were performed to evaluate the association between TMJ disorders and linear/angular menton deviation, subgrouping the studies into unilateral and bilateral cases. The evidence was certainty‐tested using the GRADE approach.

Results

The search retrieved 2371 studies, 31 of which were eligible for full‐text reading. Seven cross‐sectional clinical studies met the eligibility criteria and were included in the qualitative synthesis, comprising a total of 621 subjects (345 with TMJ disease and 276 in control group), four of which were classified as being methodologically sound. Five studies were eligible for quantitative synthesis. Linear and angular menton deviation was greater in individuals with unilateral TMJ disorders than controls (MD = 2.41 [0.33, 4.50] P = .02; I2 = 86% and MD = 2.68 [0.99, 4.38] P = .002; I2 = 0%, respectively).

Conclusions

Despite the low certainty in evidence, the present study indicated that unilateral TMJ disorders are associated with FA. However, longitudinal studies with greater certainty of evidence should be conducted to achieve a stronger estimate of this association.
Prognostic importance of RUNX1 expression for head and neck adenoid cystic carcinoma
Authors: Soares Ciro Dantas , de Cáceres Cinthia Veronica Bardález López , Rodrigues‐Fernandes Carla Isabelly , de Lima Morais Thayná Melo , de Almeida Oslei Paes , de Carvalho Maria Goretti Freire , Fonseca Felipe Paiva
Published: July 2020

Objective

In the present study, we aimed to investigate the prognostic value of RUNX1 expression in 76 patients with adenoid cystic carcinoma (ACC).

Materials and Methods

All cases were arranged in tissue microarray blocks and submitted to immunohistochemistry against RUNX1. These results were statistically correlated with clinicopathologic features, including age, gender, tumour site, tumour size, lymph node status, AJCC clinical stage, distant metastasis, treatment, recurrences, follow‐up, histologic pattern, vascular and neural invasion, all of which obtained from patient's medical records.

Results

RUNX1 was expressed in the nuclei of tumour cells, with a mean of 18.1% of positivity. Nuclear RUNX1 expression was significantly associated with AJCC clinical stage (p < .0001), solid histologic pattern (p < .0001), vascular invasion (p < .0001) and presence of local recurrence (p < .0001). Using univariate and multivariate analyses, RUNX1 nuclear expression was significantly associated with a lower disease‐free survival (p < .0001 and p = .028, respectively) and disease‐specific survival (p < .0001 and p = .018, respectively) rates.

Conclusion

In summary, RUNX1 nuclear expression may represent an indicator of unfavourable outcome for patients affected by head and neck ACC.
Pineal volume reduction in patients with mild cognitive impairment who converted to Alzheimer's disease
Authors: Matsuoka Teruyuki , Oya Nozomu , Yokota Hajime , Akazawa Kentaro , Yamada Kei , Narumoto Jin ,   for the Alzheimer's Disease Neuroimaging Initiative
Published: July 2020

Aim

Pineal parenchymal volume (PPV) reduction is one of the predisposing factors for Alzheimer's disease (AD). Therefore, PPV could be used as a predictor of developing AD in clinical settings. We investigated whether PPV in patients with mild cognitive impairment (MCI) was correlated with conversion of these patients to AD.

Methods

A total of 237 patients with MCI underwent brain magnetic resonance imaging. A two‐samplet‐test was used to compare PPV at baseline in MCI patients who converted to AD (MCI‐C) with those who did not convert (MCI‐NC). Logistic regression analysis with forced entry was used to identify predictors of AD, with variables of PPV, age, sex, education, APOE‐ε4 alleles, Mini Mental State Examination score, and total intracranial volume at baseline. Two‐way repeated‐measures analysis of variance was conducted to compare PPV at baseline and at the last examination in the MCI‐C and MCI‐NC groups.

Results

PPV in the MCI‐C group was significantly lower than that in the MCI‐NC group. In logistic regression analysis, two independent predictors of AD were identified: Mini Mental State Examination and PPV. Two‐way repeated‐measures analysis of variance revealed a significant group effect, but no time effect.

Conclusion

The pineal volume is a predictor of AD conversion, and pineal volume reduction in AD starts early when patients are still in the MCI stage. Thus, pineal volume reduction might be useful as a predictor of developing AD in clinical settings.
A cross‐sectional association of physical fitness with positive and negative affect in children and adolescents: the up & down study
Authors: del Río‐de Cózar Paula , Carbonell‐Baeza Ana , Padilla‐Moledo Carmen , Veiga Oscar L. , Esteban‐Gonzalo Laura , Mota Jorge , Castro‐Piñero José
Published: July 2020

Background

Affect and physical fitness play an important role in psychological and physical health; however, the association between those variables in youth remains unknown. The aim of the present study was to examine the influence of physical fitness on positive and negative affect in Spanish children and adolescents.

Method

Healthy young Spanish people (n = 1,490) were recruited for the present study: 542 children (n = 272 girls; mean age 9.6 years) and 948 adolescents (n = 454 girls; mean age 14.1 years) with complete baseline data on health‐related fitness tests (20 m shuttle run test, 4 × 10 m test, muscular fitness index, and physical fitness index), and positive and negative affect (Positive and Negative Affect Schedule).

Results

Higher performance on physical fitness components was associated with positive affect (β = −0.176–0.118, all P < 0.05). There was no association between all physical fitness components and negative affect (β = −0.100–0.15, all P > 0.05). There were differences on positive affect between the lowest and the highest quartile of the physical fitness index in boys (P = 0.037, Cohen's d 0.60) and girls (P = 0.004, Cohen's d = 0.69), and between the lowest and the highest quartile of muscular fitness index in girls (P < 0.001, Cohen's d = 0.76).

Conclusions

Promoting physical activity during the school years, including strength exercises to increase muscular fitness, could improve positive affect levels and thus psychological health.
A WRKY transcription factor, TaWRKY40‐D, promotes leaf senescence associated with jasmonic acid and abscisic acid pathways in wheat
Authors: Zhao L. , Zhang W. , Song Q. , Xuan Y. , Li K. , Cheng L. , Qiao H. , Wang G. , Zhou C.
Published: July 2020

Leaf senescence is a complex and precise regulatory process that is correlated with numerous internal and environmental factors. Leaf senescence is tightly related to the redistribution of nutrients, which significantly affects productivity and quality, especially in crops. Evidence shows that the mediation of transcriptional regulation by WRKY transcription factors is vital for the fine‐tuning of leaf senescence. However, the underlying mechanisms of the involvement of WRKY in leaf senescence are still unclear in wheat.

Using RNA sequencing data, we isolated a novel WRKY transcription factor, TaWRKY40‐D, which localizes in the nucleus and is basically induced by the progression of leaf senescence.

TaWRKY40‐D is a promoter of natural and dark‐induced leaf senescence in transgenic Arabidopsis thaliana and wheat. We also demonstrated a positive response of TaWRKY40‐D in wheat upon jasmonic acid (JA) and abscisic acid (ABA) treatment. Consistent with this, the detached leaves of TaWRKY40‐D VIGS (virus‐induced gene silencing) wheat plants showed a stay‐green phenotype, while TaWRKY40‐D overexpressing Arabidopsis plants showed premature leaf senescence after JA and ABA treatment. Moreover, our results revealed that TaWRKY40‐D positively regulates leaf senescence, possibly by altering the biosynthesis and signalling of JA and ABA pathway genes.

Together, our results suggest a new regulator of JA‐ and ABA‐related leaf senescence, as well as a new candidate gene that can be used for molecular breeding in wheat.
Relative economic status and mental health among Chinese adults: Evidence from the China health and retirement longitudinal study
Authors: Zhou Qin , Qin Xuezheng , Liu Gordon G.
Published: July 2020

Recent research documents increasing unhappiness (even depression) among Chinese adults despite the rapid economic growth in China. This paper explains this discrepancy by exploring the relationship between relative economic status and mental health (measured by Center for Epidemiologic Studies Depression Scale score) among the middle‐aged and elderly in China. In measuring relative economic status, we use five reference groups for comparison (i.e., relatives, colleagues, schoolmates, neighbors or villagers, and people in the same city or county). Using data from 2013 China Health and Retirement Longitudinal Study, we find that individuals with relatively lower economic status are more likely to be mentally depressed. The relationship differs across reference groups for comparisons, with the larger impacts seen from the comparison against acquaintances, while the impact of comparison to regional average is the smallest despite its frequent use in the literature. The relative economic status–mental health gradient is asymmetric; that is, the negative impact of worse relative economic status is comparatively larger and more significant than the positive impact of better relative economic status. Our results imply that reducing wealth gaps within groups of similar backgrounds can be more effective in improving people’s mental health than a general reduction of wealth inequality within the population.
Assessment of greywater reuse as a potential mitigation measure for water shortages and sanitation problems in senior high schools
Authors: Ntibrey Richard Agbo Kwabena , Fosu Gyasi Samuel , Kuranchie Francis Atta
Published: July 2020

The study assessed water shortages and its effects on sanitation in Senior High Schools using structured questionnaires involving water availability, water use pattern and perception of greywater reuse. Additionally, an observation of the sanitation situation was done to validate the responses. The study found that water availability was an issue as this caused students to use more than an hour round trip to access water resulting in poor sanitation and hygiene practices. Meanwhile, an average greywater generation rate of 14.5 L per person per day, is always disposed of despite its potential reuse. Greywater reuse was accepted by respondents as 59% proposed reusing it if available for non‐potable applications (94%) such as toilet cleaning and flushing. This is because, there is a significant association between cleanliness of the toilet facilities and usage (P < 0.05). Respondents who declined greywater reuse cited health risks (58%), uncomfortable feeling (37%) and cultural issue (5%).
Reading Intervention Practice: Effects of Print and E-Dictionary Use
Authors: Ghazali Zawiah , Habil Hadina
Published: July 2020

This study investigated reading intervention method using print and e-dictionary. In particular, the study examined the effects of print and e-dictionary usage on reading habits and reading comprehension of form sixth students in Johor. Respondents were students with low/limited English proficiency (LEP) in their second semester of sixth form program. Using a mixed method approach, data was gathered quantitatively and qualitatively. Questionnaires were utilised to collect information on students’ reading habits and reading attitudes. Reading comprehension test results were obtained from the school MUET panel examination record. The quantitative data was analysed using the SPSS software while the participants’ reading comprehension test results were analysed using Excel program. The participants’ writing reflection constituted the qualitative data. Findings show that the use of e-dictionary and print dictionary during a reading intervention program affected the reading habits and attitudes of the participants to a certain extent. The use of e-dictionary and print dictionary while reading act as an important factor in assisting LEP students to be better readers. However, there was no significant relationship between the use of e-dictionary and print dictionary and reading comprehension score. Several recommendations on intervention strategies for future research are made from the findings of this study.
A review of polyurethane as a ground improvement method
Authors: Che Lat Diana , Ali Nazri , Mohamed Jais Ismacahyadi Bagus , Mohd Yunus Nor Zurairahetty , Razali Roslizayati , Abu Talip Adrina Rosseira
Published: July 2020

Ground improvement based on lightweight materials is commonly applied as a method to overcome the problem related to excessive and differential settlement. The application of polyurethane (PU) as a ground improvement work currently increases in demand due to its well performance in many ground improvement projects. The properties and strength of different types of PU available in the market, together with the safety issues and precautions are highlighted in this paper. Due to its lightweight properties, buoyancy behavior of the lightweight foam often causes uplift which jeopardize the stability of the existing structure. Since it is applied in the ground, awareness on PU degradation needs to be emphasized. The suitability and applications of PU as one of alternative method for ground improvement works are also highlighted in this paper.
The distribution of extreme share return in different Malaysian economic circumstances
Authors: Marsani Muhammad Fadhil , Shabri Ani
Published: July 2020

This study evaluated the performance of probability distribution in various financial periods by investigating the effect of economic cycle on extreme stock return activity. Malaysian stock price KLCI data from 1994–2008 were split into three economy periods correspond to the growth, financial crisis, and the recovery. Four prevalent distributions specifically generalized lambda distribution (GLD), generalized extreme value (GEV), generalized logistic (GLO), and generalized pareto (GPA) were employed to model weekly and monthly maximum and minimum Kuala Lumpur Composite Index (KLCI) share returns. The L-moment approach was used to estimate the parameter while k-sample Anderson darling (k-ad) test was applied to measure the goodness of fit estimation. In conclusion, GLD is the most appropriate distribution representing a weekly maximum minimum return for overall three economic scenarios in Malaysia.
Mathematical analysis of plankton population dynamics
Authors: Yussof Fatin Nadiah , Maan Normah , Reba Nadzri
Published: July 2020

Harmful algal blooms (HABs) event that causes enormous economic loss and health effect raises concerns among environmentalists. In this paper, a mathematical model of interaction between nutrient, toxin-producing phytoplankton (TPP), non-toxic phytoplankton (NTP), zooplankton, and toxic chemicals is proposed to study on how the process of these HABs occurred. The model of interaction is represented by Ordinary Differential Equations (ODEs) and stability analysis of the model is conducted. Several conditions for the system to be stable around trivial and interior equilibrium point are obtained. From the analysis, it is observed that under nutrient limitation, the amounts of toxic chemicals secreted out by the TPP are increased. As a result, NTP population and zooplankton population are affected by the situation. If this situation is prolonged, this will result in the extinction of both populations. Overall, this study shows that TPP release more toxic chemicals when the nutrient is limited and gives a better understanding on the occurrence of HABs event.
Emulsion liquid membrane extraction of polyphenols compound from palm oil mill effluent
Authors: Jusoh Norela , Othman Norasikin , Geeta Gabriella , Rosly Muhammad Bukhari , Raja Sulaiman Raja Norimie , Mohamed Noah Norul Fatiha , Nor Kamarudin Khairul Sozana
Published: July 2020

Polyphenols possess many health attributes, as they are powerful antioxidants. Recovery of value-added compounds from industrial waste is a new approach in order to promote sustainability. In this study, the extraction of polyphenols from palm oil mill sterilization condensate by emulsion liquid membrane (ELM) process is proposed. The sterilization condensate was first characterized to determine the total phenolic content (TPC) in the sample. For the extraction, liquid membrane was formulated to choose the best diluent, carrier, and stripping agent. Once the formulation was successfully attempted, the extraction of polyphenols to recover polyphenols was performed. The results show that 2627.3 mg GAE/L of TPC was obtained in the condensate. During the liquid membrane formulation, palm oil was chosen as a green diluent, TBP and n-Octanol were selected as the most appropriate carriers for synergize in a composition of 8:2 by volume, while sodium hydroxide was selected as the most appropriate stripping agents to best facilitate the extraction process. The extraction and recovery performance of polyphenols showed performance of 96.5% and 31%, respectively. The findings of this study show that ELM is a potential technology to extract and recover polyphenols from palm oil mill sterilization condensate.
Uncertainties in static nuclear properties due to pairing fit procedures within Skyrme-Hartree-Fock approach
Authors: Kelvin-Lee Kai-Wen , M. Nor Nurhafiza , Koh Meng-Hock , Rezle Nor-Anita , Mohd Nor Norehan
Published: July 2020

Description of static nuclear properties is one of the main aims of theoretical nuclear physics studies. This work presents the uncertainties due to pairing fit procedure for three static nuclear quantities of rare-earth nuclei, namely the nuclear charge radius, electric quadrupole moment, and the moment of inertia. The Hartree-Fock (HF)-plus-pairing approach was employed with pairing correlations treated within the Bardeen-Cooper-Schrieffer (BCS) framework. The Skyrme SIII parametrization were chosen to approximate the effective nucleon-nucleon interaction while seniority force is used for the pairing interaction. In this work, two sets of pairing strengths obtained from different fit procedures were chosen. Calculated result shows that the moment of inertia is hugely dependent on variation of pairing strengths.
Configuration of a newly optimized multi-cyclones unit as a fine particulate emission separator in air pollution control
Authors: Hussein Norelyza , Mohd Yusof Mohd Rashid , Hashim Nur Hasyimah , Aminudin Eeydzah , Che Hassan Che Hafizah
Published: July 2020

Multi-cyclones separator, which consists of many miniature cyclones, works in the same principle as single cyclone in separation of particulate matter from flue gas. However, multi-cyclone is able to attain higher collection efficiency and concurrently avoid rapid increasing of pressure drop due to the usage of small diameter cyclone. The studies on multi-cyclones are very limited and lacking especially on its design configurations due to its confidentiality and commercial reason. Thus, a configuration of a newly optimized multi-cyclone unit named as MR-deDuster is discussed and assessed in this study. Six dimensions considered in the study include diameter of cyclone (D), diameter of vortex finder (De), length of cyclone body (Lb), length of cyclone cone (Lc), length of vortex finder (S), and diameter of dust outlet (Dd). The theoretical background of the unit was developed based on the modifications of established design equations available in literatures. The selection of the new dimension and the actual size of the unit were based on two main criteria (the performance of the unit based on its cut-diameter and the ratio of axial dimensions). The predicted cut-diameter and pressure drop of the selected dimension was 1.7 µm and 86 mm of water, respectively. Meanwhile, the optimum axial ratios of the final design were Lb/D = 1.6, S/D = 1, and Lb-S/D = 0.7, with respect to the diameter of the cyclone.
Growth of ZnO nanorods on different substrates using hydrothermal method
Authors: Mayasari Rina Dewi , Mulyono Aditya Eka , Masmui Masmui , Swathatafrijiah Wawas , Agustanhakri Agustanhakri , Yuliani Hanif , Purawiardi Ibrahim , Nuryadi Ratno
Published: July 2020

Zinc oxide (ZnO) nanorods have been grown on different substrates, i.e. gold film-coated BK-7 glass (Au-film/BK7), microscope glass slide (MGS), silicon oxide film-coated silicon (SiO2-film/Si), to investigate the effects of different substrates on its material properties. The growth process was started by dipping substrates in zinc acetate solution to fabricate a seed layer, followed by growing the ZnO nanorods in zinc nitrate tetrahydrate solution based on hydrothermal method at 95 °C for 6 hour. In this process, seed layer and ZnO nanorods were annealed at 350 °C for 2 hours. The characterization results using X-ray diffraction and field effect scanning electron microscope showed that ZnO nanorods were successfully grown homogenously and mostly in vertical direction with hexagonal wurtzite structure. The diameter size of ZnO nanorods was significantly influenced by the type of material substrate. ZnO nanorods on Au-film/BK-7 glass have the smallest diameter size of (239±51) nm, while the average diameter size of ZnO nanorods on MGS is of (269±53) nm and ZnO nanorods on SiO2-film/Si have the largest diameter size of (354±80) nm. The effect of substrates on different size of ZnO nanorods may be regarded to the intrinsic thermal conductivity of substrate material. Hence, the synthesis and growth parameters for the different substrates differ from each other and need to be optimized in order to grow ZnO nanostructures
Mixed Convection Flow Of Viscoelastic Nanofluid Past A Horizontal Circular Cylinder In Presence Of Heat Generation
Authors: Mahat Rahimah , Rawi Noraihan Afiqah , Mohd Kasim Abdul Rahman , Shafie Sharidan
Published: July 2020

The steady two-dimensional mixed convection boundary layer flow of viscoelastic nanofluid past a horizontal circular cylinder with convective boundary condition in presence of heat generation has been studied numerically. Carboxymethyl cellulose solution (CMC) is chosen as the base fluid and copper as a nanoparticle with the Prandtl number Pr = 6.2. The Tiwari and Das model has been considered in this study. The governing partial differential equations are reduced to a system of ordinary differential equations by introducing similarity transformations. The nonlinear similarity equations are solved numerically by applying the Keller-box method. The numerical results are presented graphically for different values of the parameters including the heat generation parameter, nanoparticles volume fraction, and Biot number. A systematic study is discussed to analyze the effect of these parameters on the velocity and temperature profiles as well as the skin friction and heat transfer coefficient. The thermal boundary layer shows the changes in variation behavior when the nanoparticles volume fraction, heat generation and Biot number are increased. Heat transfer coefficient is increasing function of heat generation parameter. Nanoparticles volume fraction on heat transfer coefficient have opposite effect when compared with heat generation parameter.
Significance of bio-treatment by acid washing for enlargement of arsenic desorption in indigenous arsenic-resistant bacteria from gold mine
Authors: Altowayti Wahid Ali Hamood , Dahawi Abdullah Aysh , Shahir Shafinaz
Published: July 2020

Mining activities can lead to the generation of large quantities of heavy metal, specifically arsenic which is released from a gold mine, causing widespread contamination of the ecosystem. Removal of carcinogenic and toxic arsenic from wastewater is essential for the safety of water that may be used for irrigation or drinking. In this study, three different of indigenous arsenic resistant bacterial strains were isolated from gold mine environment, Bacillus thuringiensis strain WS3, Pseudomonas stutzeri strain WS9, and Micrococcus yunnanensis strain WS11. WS9, WS3, and WS11 reached stationary phase after eight, ten, and seven hours, respectively, at 37 °C when grown in LB with arsenic. Gram staining showed WS9 as gram-negative rods, WS3 as gram-positive rods, and WS11 as gram-positive cocci. From the Silver nitrate test, WS3 and WS11 reduced As (V) to As (III) while WS9 oxidized As (III) to As (V). The desorption of arsenic using acid washing and parameters affecting the desorption of arsenic such as acid concentration, time, adsorbent dosage, and different volume of acid solution were investigated. The batch experiments were carried out using bacterial biomass cultured in LB with 2 mM arsenite (III) and 5 mM arsenate (V). Optimum conditions for desorption arsenic were determined, being 1 M acid concentration at 37 °C and 2 hours of contact with (50 mg) bacterial biomass in 100 ml acid solution. The removal of arsenite and arsenate increased after acid washing of bacterial biomass of the three strains. Consequently, desorption of arsenic using acid washing is essential for biomass regeneration.
Nanocellulose and nanoclay as reinforcement materials in polymer composites: A review
Authors: Mohd Hussin Fathin Najihah Nor , Abdul Wahab Roswanira , Attan Nursyafreena
Published: July 2020

The advancement of nanotechnology has opened a new opportunity to develop nanocomposites using nanocellulose (NC) and nanoclay (NCl). Researchers have regarded these nanocomposites as promising substitutes for conventional polymers because of their characteristic and useful features, which include exceptional strength and stiffness, low weight, and low environmental impact. These features of NC and NCl explain their multifarious applications across many sectors. Here we review NC and NCl as well as various reinforced polymer composites that are made up of either of the two nanomaterials. The structural and physicochemical properties of NC and NCl are highlighted, along with the mechanical behavior and thermal properties of NC. Current nanomaterial hybrid biopolymers for the production of novel high-performance polymer nanocomposites are also discussed with respect to their mechanical properties.
Enhanced gas separation performance of polysulfone membrane by incorporation of zeolite-templated carbon
Authors: Wijiyanti Rika , Kumala Wardhani Anggita Rara , Roslan Rosyiela Azwa , Gunawan Triyanda , Abdul Karim Zulhairun , Ismail Ahmad Fauzi , Widiastuti Nurul
Published: July 2020

The zeolite-templated carbon (ZTC) with a unique structure was utilized as a new porous filler for preparing mixed matrix membrane (MMM). The zeolite-Y used as template was synthesized via hydrothermal method. The ZTC was prepared by impregnation of sucrose into the pore of zeolite-Y, followed by carbonization and template removal. The obtained ZTC was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 isotherm analysis. Results showed that the ZTC was amorphous and possess specific surface area of 1254 m2/g and 0.95 cm3/g for total pore volume. The MMM was fabricated by adding 0.4 wt% ZTC via dry/wet spinning process with polysulfone (PSF) as the matrix. The fabricated membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermal gravimetric analysis (TGA), whereas the gas permeation properties were tested using single gases (CO2, O2, N2, CH4, and H2). The SEM results showed that incorporation of the ZTC was found to be similar as the morphological structure (dense layer and finger-like structure) of neat PSF membrane and the thermal stability was observed to be enhanced. In comparison to neat PSF membrane, uncoated PSF/ZTC MMM exhibited selectivities improvement for CO2/CH4 (290%), O2/N2(117%), CO2/N2 (219%) and H2/CH4 (272%), while coated PSF/ZTC MMM showed enhancement up to 1110%, 368%, 838%, and 802%, respectively with acceptable permeances. Compared to neat PSF membrane, profound selectivities enhancement could be achieved even with low ZTC loading inside the MMM.
Comparative study of Malaysian and Nigerian kaolin-based ceramic hollow fiber membranes for filtration application
Authors: Usman Jamilu , Othman Mohd Hafiz Dzarfan , Ismail Ahmad Fauzi , A Rahman Mukhlis , Jaafar Juhana , Abdullahi Tijjani
Published: July 2020

Ceramic membrane has gained increasing interest in water filtration application due to its inherent characteristics. Low-cost clay materials are preferred to fabricate an efficient and cost-effective ceramic membrane. Among the ceramics, kaolin displays better mechanical, thermal, and chemical properties. However, natural properties of kaolin vary from different studies. Hence, cost-effective Nigeria (NK) and Malaysia (MK) kaolins were compared to study the fabrication of kaolin hollow fiber ceramic membrane for filtration application. The effects of kaolin loading concentration (34 and 37 wt. %) and sintering temperature (1200, 1350, 1400, and 1500 °C) on kaolin membrane fabrication were also studied. XRF studies indicated that the hydroxyl silica and alumina compositions were 56.76wt.% and 41.97wt% for NK and 55.21wt.% and 40.33wt% for MK. MK exhibited intense kaolinite peak with a broad range of particle size distribution. The mechanical stability of kaolin ceramic membrane increased with the increase of sintering temperature and kaolin loading concentration. Membrane morphology also varied with MK and NK. Interestingly, 34wt% kaolin at a sintered temperature of 1350 °C produced ceramic membrane with a high water flux. A similar trend was observed in both MK and NK, where the flux of 34wt% MK and NK are 565 and 460 L/m2h, respectively.
Microbiological analysis of drinking water from water vending machines
Authors: Muhammad Mustapha Salisu , Abdul-Wahab Mohd Firdaus , Saidin Mohammad Abdul Razis , Asraf Muhammad Hariz , Nik Malek Nik Ahmad Nizam
Published: July 2020

Commercial water vending machines are gaining popularity nowadays among the general public, probably due to the ease of obtaining clean drinking water. However, improper maintenance of the machines can lead to bacterial contamination. Hence, this study aimed to investigate and determine the microbiological characteristics of drinking water from Water Vending Machines (WVM) by isolating and characterizing culturable bacteria in the water and nozzle swab samples. The samples were obtained from WVM at eight different locations around Johor Bahru, Johor, Malaysia. Several unique bacterial isolates were found, from both Gram-positive and Gram-negative groups. Polymerase chain reaction amplification and 16S rRNA sequence analysis suggested that these isolates are from Pseudomonas, Bacillus, and Stenotrophomonas genera. In situ water quality tests which include pH, conductivity, and total dissolved solids were also conducted. Two samples from the inlet source have pH and conductivity values slightly above the reference values stipulated in drinking water regulations. The findings presented here suggest the importance of regular service maintenance of the WVM to ensure that the water samples meet the standard stipulated by the authority.
Biosynthesis of gold nanoparticles-peanut shell composite for catalytic reduction of methyl blue
Authors: Shamsuddin Mustaffa , Kamaludin Fazleen , Borhamdin Suhaila
Published: July 2020

Gold nanoparticles (AuNPs) has been recognized as an active and effective catalyst for many organic transformations. Currently, there is a growing need to develop AuNPs synthesis process that avoids the use of toxic chemicals or high energy requirement. In this research, the aqueous Phaleria macrocarpa (Mahkota dewa) dried fruit extract was used in the biosynthesis of AuNPs immobilized on peanut shell powder. The peanut shell supported AuNPs was characterized by UV–visible spectroscopy (UV–Vis), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), Nitrogen (N2) adsorption-desorption and atomic absorption spectroscopy (AAS) techniques. The biosynthesized AuNPs was characterized by the appearance of a surface plasmon resonance (SPR) band at 534 nm in the UV–Vis spectrum. The XRD, TEM and TGA analytical data of AuNPs/Peanut shell composite indicated that the AuNPs with face-centred cubic (fcc) crystalline shape, mostly spherical and average particle size of 20.00 ± 4.19 nm were well dispersed on the peanut shell powder support. The FTIR analysis suggested that the C=O and O-H groups in the peanut shell powder have strong afﬁnity to bind and stabilize the AuNPs. The BET surface area of the AuNPs/Peanut shell composite catalyst determined is 35.39 m² g-1 while the BJH pore volume is 0.035 cm3 g-1 with pore diameter of 2.07 nm. AAS elemental analytical data showed the Au loading is 0.03 mmol per gram of catalyst. The catalytic performance of the AuNPs/Peanut shell composite was investigated for the reduction of aqueous methyl blue (MB) at room temperature. The reduction of MB obeyed a pseudo-first-order reaction with the highest rate constant of 0.124 min-1. The supported AuNPs/Peanut shell composite catalyst could be easily recovered and reused for at least three times without significant loss of activity
Removal of COD and ammoniacal nitrogen by banana trunk fiber with chitosan adsorbent
Authors: Suhani Noorain , Radin Mohamed Radin Maya Saphira , Abdul Latiff Ab Aziz , Nasir Nazlizan , Ahmad Baharin , Oyekanmi Adeleke Abdulrahman , Awang Halizah , Daud Zawawi
Published: July 2020

Kitchen wastewater that is discharged to the environment is one of the contributing factors to water pollution in developing countries. Adsorption is one of the emerging technology of biological treatments that is an environmentally friendly for the removal of pollutants. Banana trunk fiber with chitosan as an adsorbent was investigated for minimizing COD and ammonia from the kitchen wastewater. The raw kitchen wastewater sample used in the study was collected from the Arked food court located in Universiti Tun Hussein Onn Malaysia in Johor (Malaysia). The optimum of ratio, pH, shaking speed and contact time for COD and ammonia removal were determined. The result indicated the optimum mix ratio of fiber with chitosan, pH, shaking speed and contact time respectively was 50:50, pH 7, 125 rpm and 120 minutes based on the adsorption of COD (87%) and ammonia (90%) by banana trunk fiber with chitosan. Kinetic study of the results gave a pseudo-second order the R2 was closed to unity which was 0.998. It will significantly be considered for efficient removal of organic and nutrient pollutants present in kitchen wastewater treatment.
Age‐related changes in the biophysical and morphological characteristics of mouse cochlear outer hair cells
Authors: Jeng Jing‐Yi , Johnson Stuart L. , Carlton Adam J , De Tomasi Lara , Goodyear Richard J. , De Faveri Francesca , Furness David N. , Wells Sara , Brown Steve D. M. , Holley Matthew C. , Richardson Guy P. , Mustapha Mirna , Bowl Michael R. , Marcotti Walter
Published: July 2020

Key points

Age‐related hearing loss (ARHL) is a very heterogeneous disease, resulting from cellular senescence, genetic predisposition and environmental factors (e.g. noise exposure).

Currently, we know very little about age‐related changes occurring in the auditory sensory cells, including those associated with the outer hair cells (OHCs).

Using different mouse strains, we show that OHCs undergo several morphological and biophysical changes in the ageing cochlea.

Ageing OHCs also exhibited the progressive loss of afferent and efferent synapses.

We also provide evidence that the size of the mechanoelectrical transducer current is reduced in ageing OHCs, highlighting its possible contribution in cochlear ageing.

Outer hair cells (OHCs) are electromotile sensory receptors that provide sound amplification within the mammalian cochlea. Although OHCs appear susceptible to ageing, the progression of the pathophysiological changes in these cells is still poorly understood. By using mouse strains with a different progression of hearing loss (C57BL/6J, C57BL/6NTac, C57BL/6NTacCdh23+, C3H/HeJ), we have identified morphological, physiological and molecular changes in ageing OHCs (9–12 kHz cochlear region). We show that by 6 months of age, OHCs from all strains underwent a reduction in surface area, which was not a sign of degeneration. Although the ageing OHCs retained a normal basolateral membrane protein profile, they showed a reduction in the size of the K+ current and non‐linear capacitance, a readout of prestin‐dependent electromotility. Despite these changes, OHCs have a normal Vm and retain the ability to amplify sound, as distortion product otoacoustic emission thresholds were not affected in aged, good‐hearing mice (C3H/HeJ, C57BL/6NTacCdh23+). The loss of afferent synapses was present in all strains at 15 months. The number of efferent synapses per OHCs, defined as postsynaptic SK2 puncta, was reduced in aged OHCs of all strains apart from C3H mice. Several of the identified changes occurred in aged OHCs from all mouse strains, thus representing a general trait in the pathophysiological progression of age‐related hearing loss, possibly aimed at preserving functionality. We have also shown that the mechanoelectrical transduction (MET) current from OHCs of mice harbouring the Cdh23ahl allele is reduced with age, highlighting the possibility that changes in the MET apparatus could play a role in cochlear ageing.
Alianzas público privadas en los servicios educativos en Colombia
Authors: Dueñas-Herrera Ximena , Godoy-Mateus Silvana , Duarte-Rodríguez Jorge Leonardo , Oquendo-Victoria Diana Alexandra , Campiño-Castillo Johnny Ernesto
Published: July 2020

Las alianzas público privadas (APP) han sido reconocidas como una estrategia para aumentar la cobertura y calidad de la educación, sin embargo, su efectividad parece depender de la calidad de los contratos y del nivel de  igilancia del Estado. En este artículo se analiza la relación entre los resultados del examen Saber 11 aplicado en Colombia en 2015 y el sector o modalidad de los colegios. Con base en modelos multinivel, se concluye que, entre los estudiantes con alta probabilidad de pertenecer al sector oficial, aquellos que asisten a colegios oficiales evidencian un mejor desempeño promedio.
The Influence of Internal Heat Storage Material and Longitudinal Fins on a Double-Pass Solar Air Heater Performance
Authors: Sivarathinamoorthy H. , Sureshkannan G.
Published: July 2020

This study presents the overall performance of a double-pass solar air heater (DPSAH) with three different configurations: (i) double-pass solar air heater without fins and heat storage (DPSAHWF), (ii) double-pass solar air heater with longitudinal fins and without heat storage (DPSAHLF), and (iii) double-pass solar air heater with longitudinal fins and heat storage (DPSAHLFHM). Five longitudinal fins on the upper channel and granular carbon at the bottom of lower channel as heat storage material were used for the analysis. Each configuration was examined for the following flowrates of air (ṁ1 = 0.008 kg/s, ṁ2 = 0.012 kg/s, and ṁ3 = 0.016 kg/s). The results show an improvement in thermal efficiency with an increase in the air flowrate. The outlet air temperature increases considerably with a decrease in flowrate, for all the three orientations. The lowest and the highest efficiencies during the peak sunshine hours were recorded as 33% and 65% for the conventional heater and the heater with fins and heat storage material, respectively. A maximum of 849 W/m2 of solar intensity was recorded during the test period. The system is also examined for thermal discharge after the sunshine hours to determine the effectiveness of the heat storage material.
Analysis of Designer Emotions in Collaborative and Traditional Computer-Aided Design
Authors: Zhou Jinxuan (Janice) , Phadnis Vrushank , Olechowski Alison
Published: July 2020

We developed a new method to link designer emotions with corresponding designer activities while using computer-aided design (cad) software. Our method employs automated facial emotion detection software and cursor tracking. We applied this method via an experiment with nine participants, each working with the same synchronously collaborative cad platform, and assigned a series of cad tasks in one of two distinct working styles: single participants working by themselves and paired participants working together. We analyzed and compared trends in emotion for these two working styles. Pairs, on average per person, experienced higher levels of emotion (measured as joy, sadness, anger, contempt, fear, and surprise) than individuals. We linked occurrences of each emotional response to their antecedent activities in the cad environment (navigating the model tree, sketching in the graphics area, making selections in the feature menu, and communicating using the chat window). Using a logistic regression analysis, we revealed statistically significant trends linking emotions and cad events, and we found that some emotions are more likely to occur with certain designer actions in the cad software. The method and conclusions presented in this paper allow us to better understand designer emotions in traditional and collaborative cad, which link to the established relationships between emotion and designer satisfaction, creativity, performance, and other outcomes increasingly valued by engineering designers and managers in virtually collaborative environments.
Online Data-Driven Prediction of Spatio-Temporal System Behavior Using High-Fidelity Simulations and Sparse Sensor Measurements
Authors: Zhao X. , Azarm S. , Balachandran B.
Published: July 2020

Predicting the behavior or response for complicated dynamical systems during their operation may require high-fidelity and computationally costly simulations. Because of the high computational cost, such simulations are generally done offline. The offline simulation data can then be combined with sensors measurement data for online, operational prediction of the system's behavior. In this paper, a generic online data-driven approach is proposed for the prediction of spatio-temporal behavior of dynamical systems using their simulation data combined with sparse, noisy sensors measurement data. The approach relies on an offline–online approach and is based on an integration of dimension reduction, surrogate modeling, and data assimilation techniques. A step-by-step application of the proposed approach is demonstrated by a simple numerical example. The performance of the approach is also evaluated by a case study which involves predicting aeroelastic response of a joined-wing aircraft in which sensors are sparsely placed on its wing. Through this case study, it is shown that the results obtained from the proposed spatio-temporal prediction technique have comparable accuracy to those from the high-fidelity simulation, while at the same time significant reduction in computational expense is achieved. It is also shown that, for the case study, the proposed approach has a prediction accuracy that is relatively robust to the sensors’ locations.
Uncertainty Quantification of Mode Shape Variation Utilizing Multi-Level Multi-Response Gaussian Process
Authors: Zhou K. , Tang J.
Published: July 2020

Mode shape information plays the essential role in deciding the spatial pattern of vibratory response of a structure. The uncertainty quantification of mode shape, i.e., predicting mode shape variation when the structure is subjected to uncertainty, can provide guidance for robust design and control. Nevertheless, computational efficiency is a challenging issue. Direct Monte Carlo simulation is unlikely to be feasible especially for a complex structure with a large number of degrees-of-freedom. In this research, we develop a new probabilistic framework built upon the Gaussian process meta-modeling architecture to analyze mode shape variation. To expedite the generation of input data set for meta-model establishment, a multi-level strategy is adopted which can blend a large amount of low-fidelity data acquired from order-reduced analysis with a small amount of high-fidelity data produced by high-dimensional full finite element analysis. To take advantage of the intrinsic relation of spatial distribution of mode shape, a multi-response strategy is incorporated to predict mode shape variation at different locations simultaneously. These yield a multi-level, multi-response Gaussian process that can efficiently and accurately quantify the effect of structural uncertainty to mode shape variation. Comprehensive case studies are carried out for demonstration and validation.
Low-Frequency Acoustic Absorption of 3D Printed Cylinders
Authors: Slaboch Paul E. , Kaye Sophie , Casavant Ethan
Published: July 2020

Attenuating low-frequency sound is often problematic, due to the large space required for common absorptive materials to mitigate such noise. However, natural hollow reeds are known to effectively attenuate low frequencies while occupying relatively little space compared to traditional absorptive materials. The present study determines the effect of varied outer diameter and outer spacing on the 200–1600 Hz acoustic absorption of 3D printed arrays of hollow cylinders. Samples were tested in a 100-mm diameter normal incidence impedance tube such that cylinder length was oriented perpendicular to the incoming plane wave. By varying only one geometric element of each array, the absorption due to any parameter can be assessed individually. It was found that minimizing cylinder spacing and maximizing cylinder diameter resulted in increased overall absorption and produced more focused absorption peaks at specific low frequencies. Wider cylinder spacing produced a broader absorptive frequency range, despite shifting upward in frequency. Thus, manipulating these variables can specifically target absorption for low-frequency noise that would otherwise disturb listeners.
An experimental analysis of acoustic input impedance of a narrow pipe with low Mach number flow and thermal gradient
Authors: Zaker Ashkan , Gibiat Vincent , Guilain Stephane , A. Shirvan Reza
Published: July 2020

In this paper, the normalized acoustic input impedance of a narrow pipe with a strong axially non-homogeneous thermal profile subjected to low Mach number flow of up to 0.03 M is studied. The analysis is done experimentally, using the two-microphone three-calibration technique and the results are compared with numerical simulations, using an industrial finite element package. The main application of this study is in the acoustic design of water-cooled charge-air coolers in internal combustion engines. The measurements are done on an effectively semi-infinite narrow pipe. It is shown that neglecting the flow effect in the calibration process of narrow pipes can significantly increase the measurement error. The results show that although the direct modification of the normalized acoustic input impedance due to low Mach number flow is negligible, the flow exerts an indirect but significant effect on this parameter by modifying the thermal gradient profile. Therefore, taking this effect into account can help to achieve an improved acoustical design of engine intake lines.