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Neutral Delay Differential Equations: Oscillation Conditions for the Solutions

Omar Bazighifan, Hammad Alotaibi, Abd Allaah A. Mousa
2021 Symmetry  
The purpose of this article is to explore the asymptotic properties for a class of fourth-order neutral differential equations. Based on a comparison with the differential inequality of the first-order, we have provided new oscillation conditions for the solutions of fourth-order neutral differential equations. The obtained results can be used to develop and provide theoretical support for and to further develop the study of oscillation for a class of fourth-order neutral differential
more » ... Finally, we provide an illustrated example to demonstrate the effectiveness of our new criteria.
doi:10.3390/sym13010101 fatcat:p6da3jailvc7jnbysynkrnrpii

Oscillation of Emden–Fowler-Type Neutral Delay Differential Equations

Shyam Sundar Santra, Taher A. Nofal, Hammad Alotaibi, Omar Bazighifan
2020 Axioms  
In this work, we consider a type of second-order functional differential equations and establish qualitative properties of their solutions. These new results complement and improve a number of results reported in the literature. Finally, we provide an example that illustrates our results.
doi:10.3390/axioms9040136 fatcat:n62or3ym5ze27no7vde4w7uwsa

Perspectives of tissues in silico

Seddik Hammad, Mosaab A Omar, Mohammed F Abdallah, Hassan Ahmed
2015 EXCLI Journal : Experimental and Clinical Sciences  
Over the past decade much effort has been invested into the development of in vitro systems as alternatives to animal experiments (Hammad et al., , 2014a Hammad, 2013; Godoy et al., 2010 Godoy et al.,  ...  In the first step spatio-temporal models are generated from reconstructions (Hammad et al., 2014c) . For this purpose the individual cell serves as the smallest unit.  ... 
doi:10.17179/excli2015-219 pmid:26535034 pmcid:PMC4614268 fatcat:z7w3bxiawjh7dcjaz7cw2d2j6i

New Oscillation Criteria for Neutral Delay Differential Equations of Fourth-Order

Saeed Althubiti, Omar Bazighifan, Hammad Alotaibi, Jan Awrejcewicz
2021 Symmetry  
New oscillatory properties for the oscillation of solutions to a class of fourth-order delay differential equations with several deviating arguments are established, which extend and generalize related results in previous studies. Some oscillation results are established by using the Riccati technique under the case of canonical coefficients. The symmetry plays an important and fundamental role in the study of the oscillation of solutions of the equations. Examples are given to prove the significance of the new theorems.
doi:10.3390/sym13071277 fatcat:c4ujnl5uobaqfn4vgdbxwabraq

Cultural Eating Practices among Jordanians

Hiba Bawadi, Zaid Al-Hamdan, Hala Bawadi, Omar Ershidat, Fwzieh Hammad, Lana Agraib
2012 Food and Nutrition Sciences  
Culture has an enormous impact on individuals' food choices and practices. This research aimed to screen cultural eating practices among Jordanians. Jordanian adults (N = 4750) completed a survey with regard to common eating practices in Jordan. Practices were classified into 4 themes, namely regular eating practices (7 practices), seasonal eating practices (4 practices), eating practices in social occasions (6 practices), and eating practices in religious occasions (10 practices).
more » ... , most nutritional practices during Ramadan and Eids (religious occasions) were agreed upon from 100% of the participating sample. In conclusion, culture in Jordan has a huge influences eating practices and food choice. Negative culture's influence over eating practices may exist, thus increasing awareness about unhealthy eating practices related to culture is necessary.
doi:10.4236/fns.2012.36106 fatcat:py27rzgv25dqzce6g3puxibenm

Software Security Validation through Regular Expressions

Omar Abahussain, Mustafa Hammad, Fawzi Albalooshi
2022 International Journal of Computing and Digital Systems  
In modern society, software security has become an essential part of most software systems. As nowadays, new systems roll out more than ever, cybercriminals and unethical hackers tend to target those new systems to abuse and exploit its vulnerability to achieve a specific goal regardless of the consequences. Thus, validating software security is a challenging task and of crucial importance. The paper aims to find an optimal logical approach to test and validate software security through static
more » ... nalysis using regular expressions to optimize and secure the source code of the software.
doi:10.12785/ijcds/110156 fatcat:uieyxqe33vdxrhg7unghs4nddu

Gebel-criteria for risk assessment in nanotoxicology

Seddik Hammad, Ahmed M Abdou, Mosaab A Omar
2014 EXCLI Journal : Experimental and Clinical Sciences  
* Corresponding author: Seddik Hammad.  ... 
pmid:26417332 pmcid:PMC4464467 fatcat:phdnhnvrhzfibncixnpkqczcw4

Accelerated Dynamic MRI Using Kernel-Based Low Rank Constraint

Omar Arif, Hammad Afzal, Haider Abbas, Muhammad Faisal Amjad, Jiafu Wan, Raheel Nawaz
2019 Journal of medical systems  
We present a novel reconstruction method for dynamic MR images from highly under-sampled k-space measurements. The reconstruction problem is posed as spectrally regularized matrix recovery problem, where kernel-based low rank constraint is employed to effectively utilize the non-linear correlations between the images in the dynamic sequence. Unlike other kernel-based methods, we use a single-step regularized reconstruction approach to simultaneously learn the kernel basis functions and the
more » ... ts. The objective function is optimized using variable splitting and alternating direction method of multipliers. The framework can seamlessly handle additional sparsity constraints such as spatio-temporal total variation. The algorithm performance is evaluated on a numerical phantom and in vivo data sets and it shows significant improvement over the comparison methods.
doi:10.1007/s10916-019-1399-x pmid:31278506 fatcat:rtugnj2bbrh5fbhuhhtlddlpcm


Noha Kamal, Abdallah Hammad, Talaat Salem, Mohie Omar
2019 JES. Journal of Engineering Sciences  
In Egypt, the current water quality monitoring program involves thorough physio-chemical and biological analyses. However, there is still a lack of real-time water quality data that influences the urgent decision making process. The field acquisition of such data has still been costly, lengthy and laborious. Therefore, this paper aims to present a low-cost and labor-saving Early Warning Framework (EWF) for water quality monitoring of the River Nile based on the Internet of Things (IOT). A newly
more » ... developed Prototype was introduced to monitor the in-situ water quality parameters; pH, turbidity and temperature at a pilot location along the River Nile within Egypt. The same parameters were also monitored using the current state-of-the-art multi-probe EXO.Then, both sets of data measurements were sent to a real-time monitoring control center for comparison and calibration. The comparison results revealed that there is no significant difference between the two measurements according to a statistical analysis done using the Minitab 16 statistical model. The Root Mean Squared Error (RMSE) values showed that the error percentages were accepted for the three monitored parameters (0.19 for pH, 0.056 for temperature, and 0.52 for turbidity). Moreover, the overall cost of the developed Prototype including sensors, raspberry Pi and all other expenses was found to be only 197 $ as compared to 11,130 $ when using EXO. Accordingly, it could be concluded that the developed Prototype can provide a low-cost early warning system for water quality monitoring. Finally, it is strongly recommended to install developed real-time water quality monitoring stations as economic wireless hotspots at a number of strategic sites along the River Nile within Egypt.
doi:10.21608/jesaun.2019.115742 fatcat:4vwtcc6idfgrnhemtxrvotiylm

Recent developments in animal sciences

Seddik Hammad, Isabelle Sobor, Mohammed F Abdallah, Ahmed A A Abdel-Wareth, Mohammad S Al-Aboody, Mosaab A Omar
2015 EXCLI Journal : Experimental and Clinical Sciences  
A limitation of in vitro data is that comprehensive studies on the in vivo relevance of responses observed in vitro are rare Ghallab and Bolt, 2014; Hammad et al., 2014; Hammad, 2013) .  ... 
doi:10.17179/excli2015-325 pmid:26600748 pmcid:PMC4652631 fatcat:624xmimmdrcn3gw6c433akqjdq


Mohamed S. Kheir, Hany F. Hammad, Abbas S. Omar
2012 Progress in Electromagnetics Research B  
A new technique for broadband material characterization, using a whispering-gallery-mode (WGM) resonator, is proposed. The resonant perturbation method is applied for the measurement of both the dielectric constant and loss tangent of various types of materials and over a wide frequency band. A comprehensive study on the reliability of using such technique, via simulations and measurements, is conducted as well. The feasibility of this device in sensing small variations of the dielectric
more » ... ies of the material is investigated. Furthermore, the geometry of the resonator is slightly modified to fit liquid materials as well. This can be a promising solution for sensing human-body tissues or liquids such as blood or urine due to the sensitive nature of these resonators. The experimental setup is successfully utilized to measure the dielectric constant of a water droplet as a liquid sample as well as different material samples of arbitrary shapes and dielectric properties. The measurements are performed over the whole X-and K-bands where the obtained results are with a maximum deviation of only 3.3% for solids and 4.5% for liquids.
doi:10.2528/pierb12070508 fatcat:44ws3qjy3bhx7k7tn4q3hultri

Improving the Sensitivity of Chipless RFID Sensors: The Case of a Low-Humidity Sensor

Giada Marchi, Viviana Mulloni, Omar Hammad Ali, Leandro Lorenzelli, Massimo Donelli
2021 Electronics  
This study is supposed to introduce a valid strategy for increasing the sensitivity of chipless radio frequency identification (RFID) encoders. The idea is to properly select the dielectric substrate in order to enhance the contribution of the sensitive layer and to maximize the frequency shift of the resonance peak. The specific case of a chipless sensor suitable for the detection of humidity in low-humidity regimes will be investigated both with numerical and experimental tests.
doi:10.3390/electronics10222861 fatcat:phpzeq2khveyhlnhn45paqr7ha

Prevalence and severity of plaque-induced gingivitis in a Saudi adult population

Majdy M Idrees, Saleh N Azzeghaiby, Mohammad M Hammad, Omar B Kujan
2014 Saudi Medical Journal  
To evaluate the prevalence and severity of plaque-induced gingivitis among a Saudi adult population in Riyadh region. Three hundred and eighty-five eligible participants in this cross-sectional study were recruited from routine dental patients attending the oral diagnosis clinic at Al-Farabi College in Riyadh, Saudi Arabia from June 2013 to December 2013. A clinical examination was performed by 2 dentists to measure the gingival and plaque indices of Löe and Silness for each participant. The
more » ... valence of gingivitis was 100% among adult subjects aged between 18-40 years old. Moreover, the mean gingival index was 1.68±0.31, which indicates a moderate gingival inflammation. In fact, males showed more severe signs of gingival inflammation compared with females (p=0.001). In addition, the mean plaque index was 0.875±0.49, which indicates a good plaque status of the participants. Interestingly, the age was not related either to the gingival inflammation (p=0.13), or to the amount of plaque accumulation (p=0.17). However, males were more affected than females (p=0.005). The results of this study show that plaque accumulation is strongly associated with high prevalence of moderate to severe gingivitis among Saudi subjects.
pmid:25399215 pmcid:PMC4362151 fatcat:zjwaj4wug5fqbcrxr5fpwudqvq

On the qualitative behavior of the solutions to second-order neutral delay differential equations

Shyam Sundar Santra, Hammad Alotaibi, Omar Bazighifan
2020 Journal of Inequalities and Applications  
AbstractDifferential equations of second order appear in numerous applications such as fluid dynamics, electromagnetism, quantum mechanics, neural networks and the field of time symmetric electrodynamics. The aim of this work is to establish necessary and sufficient conditions for the oscillation of the solutions to a second-order neutral differential equation. First, we have taken a single delay and later the results are generalized for multiple delays. Some examples are given and open problems are presented.
doi:10.1186/s13660-020-02523-5 fatcat:ab6gygm5szbrhlg7l6yxcnvja4

Maspin, Syndecan-1, and Ki-67 in the Odontogenic Keratocyst: An Immunohistochemical Analysis

Huda M. Hammad, Omar M. Nagrash, Rima A. Safadi
2020 International Journal of Dentistry  
The odontogenic keratocyst (OKC) is a controversial lesion that was reclassified as a tumor with the name "keratocystic odontogenic tumor" in 2005. The reclassification was revoked recently in 2017, with a conclusion on the need for further studies on the subject. In this study, the expressions of an important regulatory protein (maspin), an important integral membrane proteoglycan (syndecan-1), and a universal proliferation marker (Ki-67) in the epithelium of the OKC were investigated in
more » ... ison with the dentigerous cyst (DC) and ameloblastoma (AB). Twenty-six OKCs, eleven DCs, and ten conventional ABs were immunohistochemically stained for maspin, syndecan-1, and Ki-67. ImageJ was used to analyze the positivity of maspin and syndecan-1. The Ki-67 score was calculated as the percentage of positive nuclei in 5 high power fields. Analysis of variance (ANOVA) test and Student t-test were used as appropriate. Lower expressions of maspin were noted in OKC and DC compared to those in AB, and lower expressions of syndecan-1 were noted in OKC and AB compared to those in DC. The differences, however, did not reach statistical significance (ANOVA and t-test: P>0.05). The Ki-67 score was significantly higher in OKC than in DC (t-test: P<0.05), and not significantly different from AB (t-test: P>0.05). In conclusion, expressions of maspin and syndecan-1 are not strongly representative of differences in behavior between OKC, AB, and DC. However, the expression of Ki-67 indicates comparable proliferative activities of OKC and AB, which are higher than that of DC. Further investigation on the biologic behavior of OKC is still recommended to arrive at more specific conclusions regarding its classification.
doi:10.1155/2020/7041520 pmid:32733563 pmcid:PMC7376412 fatcat:ov7rqiha4ff3hmacfqogys6joa
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