STUDIES ON HIGH-PERFORMANCE THERMOSETS AND THEIR INTERFACE AND INTERPHASE WITH CARBON-NANOTUBES

Materials with higher strength to weight ratio than the current state of the art (SOA) carbon fiber reinforced plastics (CFRP) are desired by NASA to support affordable space exploration, including human travel to mars and beyond. The carbon nanotube-polymer (CNT-polymer) composites are expected to have significantly better mechanical properties than the current SOA CFRP and qualify as a potential system for achieving the target mechanical properties in materials required to support human travel to mars. CNT containing polymer composites, however, have some limitations, one of which is the load transfer at the CNT- polymer interface. The interface plays a critical role in determining the overall macroscale properties of the composite. While, significant attention has been directed to this end the CNTs in the composites have not yet reached their full potential. There are several aspects of the CNT-polymer composites which can help create the next generation of high strength and lightweight materials, to help support human travel to mars and beyond. These include, (a) improving the fracture toughness of the polymer resin, (b) understanding and optimizing the CNT-polymer interactions, (c) understanding the effects of CNTs on the polymer cure reactions, which consequently can alter the mechanical properties of the composite, (d) modifying the CNT-polymer interface-interphase through surface treatment and sizing, (e) understanding the effects of amorphous carbon on the CNT-polymer interface-interphase. Herein, the first part of the dissertation focuses on the effect of processing on the molecular structure and the properties of a multi-component aerospace grade bismaleimide (BMI) resin, containing no CNTs, and is discussed in Chapter 2. Materials in nature such as nacre that are made of mechanically inferior building blocks exhibit extreme toughness at the macro scale because of the geometry and arrangement of their constituents. Taking a cue from these systems, we have investigated whether the molecular rearrangement in a heterogeneous BMI system can alter toughness at the macro scale. To this end, a multicomponent BMI system is processed by using (a) a melt and cast (termed Melt) approach and (b) a dual asymmetric centrifuge based high-speed shear mixing (termed HSSM) approach to enforce molecular rearrangement. FTIR, Raman, and NMR spectroscopies have been used to study the molecular rearrangement upon HSSM processing. Small-angle X-ray scattering has been used to study the effect of processing on the molecular arrangement of the BMI. The second part of this dissertation focuses on the structure, process and properties of CNT modified BMI, with tailored interface-interphase and is discussed in Chapter 3. With the recent large-scale production and availability of the CNT macro-assemblies in the yarn, tape and sheet forms, CNT-polymer composites could now be prepared through conventional CFRP manufacturing techniques such as filament winding. It is however expected that the resin dominated properties, such as the inter and intra laminar fracture toughness in these CNT- polymer composites would still remain relatively weak, as they have been for the CFRPs. Modifying the resin with CNTs is an attractive route for further improving the resin properties. Herein, CNT- BMI nanocomposites using three different CNTs and via two different processing routes, have been prepared and studied. The third part of this dissertation focuses on the effects that the CNT have on the cure of the BMI, as well as the effects that the cure of BMI has on the CNTs, in the nanocomposites containing up to 40 wt% CNTs, and is discussed in Chapter 4. CNTs can interact with the BMI system through the NH-π, π-π, CH-π, and OH-π, non-covalent interactions. The individual components of the BMI however can have exclusive non-covalent interactions with the CNTs. For example, in a BMI system containing 4,4'- bismaleimidodiphenylmethane (BDM) and diallylbisphenol A (DABA) components, only the BDM component contains the maleimide functional group which can potentially interact with the CNTs through the NH-π bonding, while only the DABA component, containing the OH functional group can potentially interact with the CNTs through the OH-π interactions. The potential for the preferential stacking of the different BMI components around the CNTs, can have important implications on the cure behavior of the BMI in the nanocomposite and consequently on the overall mechanical properties of the nanocomposite. Herein, two different types of CNTs in the sheet form: unbaked and baked (termed as UB and B CNT), have been employed. The effects of the varying CNT content on the inter-CNT spacing, cure reactions of the BMI, compression of CNTs and the thermomechanical properties of the nanocomposites have been investigated. The thermomechanical results and the theoretical calculations have then been used to estimate the interphase thickness of the CNT- BMI nanocomposites. The fourth part of this dissertation focuses on sizing and tailoring the CNT- BMI interface - interphase using a carbon fiber sizing, and is discussed in Chapter 5. Sizing of carbon and glass fibers is a critical step in the manufacturing of their respective composites with polymers and has led to improved interfacial shear strength (IFSS), inter-laminar shear strength (ILSS) and fracture toughness of the composites. As the CNT-polymer composites could now be prepared through conventional CFRP manufacturing techniques such as filament winding, the question is, could we integrate another critical step of the conventional CFRP manufacturing, i.e., ‘sizing’, to the CNT-polymer composite preparation to tailor the CNT-polymer interface-interphase? To be able to answer that question, we first need to understand the sizing-CNT interactions and reactions. To this end, herein, the effects that (a) CNTs, (b) the degree of functionalization and defects (DOFD) in the CNTs and (c) the sizing content, have on the sizing cure reaction and cure kinetics have been evaluated. CNTs with three different DOFD have been employed. The sizing coated CNTs have then been used to prepare nanocomposite films with a high- performance aerospace grade bismaleimide (BMI) resin. Overall three different types of CNT- BMI interface-interphase have been prepared and studied in nanocomposites containing 60 wt% CNTs: (a) pristine CNT- BMI, (b) functionalized CNT- BMI, and (c) sizing coated functionalized CNT- BMI. The effect of CNT, CNT functionalization and sizing coated CNTs on the BMI cure reactions, thermomechanical properties and the molecular heterogeneity and hierarchy of the nanocomposites have been studied and discussed. Finally, CNTs may contain amorphous carbon, among other impurities which consequently could interfere with the interfacial interactions of the CNT and the polymer. While such impurities are expected to have a negative effect on the polymer-CNT interface, quantitative evidence of the extent of such negative effects is lacking. Herein, the effect that the amorphous carbon and the baking of CNTs to remove the amorphous carbon have, on the interfacial stress transfer with the polyurea matrix has been studied and discussed in Chapter 6. During CNT synthesis, by products such as amorphous carbon may be formed which consequently could interfere with the interfacial interactions of the CNT and the polymer. While such impurities are expected to have a negative effect on the polymer-CNT interface, quantitative evidence of the extent of such negative effects is lacking. Herein, the difference in interfacial straining has been studied in composites of polyurea with two types of CNT sheets: (a) sheets containing amorphous carbon (termed as unbaked CNT sheet) and (b) sheets that are thermally treated to remove amorphous carbon (termed as baked CNT sheet). The understanding of the effects of the amorphous carbon and the baking treatment, based on the CNT- polyurea system should be translatable to other CNT-polymer system, including the CNT-BMI system. It is expected that these studies will provide guidance for the manufacturing of CNT, or CNT and carbon fiber hybrid based laminates that will ultimately meet NASA mechanical property goals.Ph.D

Construction of a virus-induced gene silencing system based on Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV)

[no abstract

Lymphocytes Prediction of Homeostasis Model Assessment of Beta-cells Function (HOMA-B) and C-peptide Level during Pregnancy: New Insight into Beta-cells Proliferation and Insulin Sensitivity

هدفت هذه الدراسة الكشف عن علاقة الببتيد سي ونموذج تقييم توازن وظيفة خلايا بيتا (HOMA2-B%) مع المؤشرات الحيوية الالتهابية في النساء الحوامل بالمقارنة بالنساء غير الحوامل. تم استخدام الأمصال لـ 28 امرأة حامل في أواخر الحمل مقابل 27 امرأة غير حامل (مجموعة التحكم) لتقديرالببتيد سي وهورمونات الغدة الدرقية (T3) و (T4) بواسطة مقايسة الممتز المناعي المرتبط بالإنزيم (ELISA) وتم تقدير سكر الدم الصامي (FBS) بواسطة المحلل التلقائي Biolis 24i، وتعداد خلايا الدم (C.B.C) بواسطة جهاز تحليل أمراض الدم وتم حساب HOMA2-B% ونموذج تقييم توازن حساسية الأنسولين HOMA2-S%)) باستخدام قيم الببتيد سي بدلا من قيم الانسولين. تم إجراء المقارنات والارتباطات واختبارات تحليل الانحدار بواسطة برنامج الحزمة الإحصائية للعلوم الاجتماعية (SPSS). في مجموعة النساء الحوامل، زادت HOMA2-B%  وT3 وT4 وخلايا الدم البيضاء (WBC) وخلايا MID والخلايا المحببة (GRAN) بشكل ملحوظ (p-values˂0.05)، بينما ارتفع مستوى الببتيد سي حوالي 11٪ مقارنة بمجموعة التحكم. انخفضت الخلايا الليمفاوية وخلايا الدم الحمراء (RBC) والصفائح الدموية (PLT) والهيموغلوبين (HGB) بشكل ملحوظ (p-values˂0.05). الخلايا الليمفاوية تنبأت بمستوى كلاً من  HOMA2-B%والببتيد سي أثناء الحمل ( R2 = 0.516 ، p ˂0.0004 ؛ R2 = 0.31 ، p= 0.009 على التوالي). يوضح التنبؤ بمستويات HOMA2-B%  والببتيد سي بواسطة تعداد الخلايا الليمفاوية أن التكيف في خلايا بيتا قد يكون جزءًا من آلية النظام الدفاعي للجسم ضد الإجهاد التأكسدي، وهذا يسلط الضوء على نظرة جديدة حول تكاثر خلايا بيتا أثناء الحمل وحساسية الأنسولين.This work aims to detect the associations of C-peptide and the homeostasis model assessment of beta-cells function (HOMA2-B%) with inflammatory biomarkers in pregnant-women in comparison with non-pregnant women. Sera of 28 normal pregnant women at late pregnancy versus 27 matched age non-pregnant women (control), were used to estimate C-peptide, triiodothyronine (T3), and thyroxin (T4) by Enzyme-linked-immunosorbent assay (ELISA), fasting blood sugar (FBS) by automatic analyzer Biolis 24i, hematology-tests by hematology analyzer and the calculation of HOMA2-B% and homeostasis model assessment of insulin sensitivity (HOMA2-S%) by using C-peptide values instead of insulin. The comparisons, correlations, regression analysis tests were performed by the software of statistical package for the social sciences (SPSS). In pregnant women group, HOMA2-B%, T3, T4, white blood cell (WBC), MID cells, granulocytes (GRAN) increased significantly (p-values˂0.05), while C-peptide level raised about 11% compared to control. Lymphocytes, red blood cells (RBC), platelets (PLT) and hemoglobin (HGB) decreased significantly (p-values˂0.05). Lymphocytes predicted both HOMA2-B% and C-peptide level during pregnancy (R2 =0.516, p ˂0.0004; R2=0.31, p ˂0.009 respectively). Prediction of HOMA2-B% and C-peptide levels by lymphocytes account clarifies that the adaptation in beta-cells might be a part of the defense system mechanism of the body against oxidative stress, and this highlights new insight on the proliferation of beta-cells during pregnancy and insulin sensitivity

Analysis and data processing to identify COVID-19 patients with spontaneous respiratory capacity and predict their mortality

L’objectiu del present projecte és aportar noves opcions de disseny d’una eina per l’ajuda de presa de decisions, com també l’optimització dels mètodes d’anàlisi de dades presentats prèviament en l’article científic “Predictors of failure with high‐flow nasal oxygen therapy in COVID‐19 patients with acute respiratory failure: a multicenter observational study”[13] i addicionalment proporcionar un model predictiu de mortalitat. L’estudi es centra en una base de dades de pacients contagiats amb COVID‐19 als que se’ls havia administrat oxigenoteràpia d’alt flux amb la finalitat de crear un model de dades predictiu capaç d’inferir la necessitat d’intubació invasiva donades les condicions clíniques inicials del pacient durant el primer dia en l’UCI. Per desenvolupar aquest model, es varen recol∙lectar dades de 5 hospitals en Espanya i Andorra durant els primers mesos de la primera ona de la pandèmia. D’aquest procés es va obtenir una base de dades de 1129 pacients, dels quals 259 van rebre ox‐ igenoteràpia d’alt flux. Amb l’objectiu d’aprofitar aquesta base de dades, en aquest projecte s’analitzen les dades dels esmentats 259 pacients per desenvolupar dos models predictius per estimar la prob‐ abilitat d’intubació i de mortalitat. Amb aquesta finalitat, s’ha establert un mètode més eficient per provar i validar ràpidament diferents tipus d’algoritmes d’aprenentatge automàtic. Els mètodes utilitzats per obtenir el model predictiu de la mortalitat són també aplicables a altres variables, en conseqüència es desenvolupa un model alternatiu de predicció d’intubació. Els resultats obtinguts amb aquest nou model són comparables amb els de l’estudi anterior [13] i a més aporten alternatives viables per la millora en el desenvolupament d’eines que ajuden a la presa de decisions al personal sanitari, basades en tecnologies de Machine Learning. S’obren nous camins on el coneixement del processament de la informació pot aportar soluciones a les necessitats urgents i reals de la societat.L’objectiu del present projecte és aportar noves opcions de disseny d’una eina per l’ajuda de presa de decisions, com també l’optimització dels mètodes d’anàlisi de dades presentats prèviament en l’article científic “Predictors of failure with high‐flow nasal oxygen therapy in COVID‐19 patients with acute respiratory failure: a multicenter observational study”[13] i addicionalment proporcionar un model predictiu de mortalitat. L’estudi es centra en una base de dades de pacients contagiats amb COVID‐19 als que se’ls havia administrat oxigenoteràpia d’alt flux amb la finalitat de crear un model de dades predictiu capaç d’inferir la necessitat d’intubació invasiva donades les condicions clíniques inicials del pacient durant el primer dia en l’UCI. Per desenvolupar aquest model, es varen recol∙lectar dades de 5 hospitals en Espanya i Andorra durant els primers mesos de la primera ona de la pandèmia. D’aquest procés es va obtenir una base de dades de 1129 pacients, dels quals 259 van rebre ox‐ igenoteràpia d’alt flux. Amb l’objectiu d’aprofitar aquesta base de dades, en aquest projecte s’analitzen les dades dels esmentats 259 pacients per desenvolupar dos models predictius per estimar la prob‐ abilitat d’intubació i de mortalitat. Amb aquesta finalitat, s’ha establert un mètode més eficient per provar i validar ràpidament diferents tipus d’algoritmes d’aprenentatge automàtic. Els mètodes utilitzats per obtenir el model predictiu de la mortalitat són també aplicables a altres variables, en conseqüència es desenvolupa un model alternatiu de predicció d’intubació. Els resultats obtinguts amb aquest nou model són comparables amb els de l’estudi anterior [13] i a més aporten alternatives viables per la millora en el desenvolupament d’eines que ajuden a la presa de decisions al personal sanitari, basades en tecnologies de Machine Learning. S’obren nous camins on el coneixement del processament de la informació pot aportar soluciones a les necessitats urgents i reals de la societat.The goal of the present dissertation is to provide new design options for tools to help decision mak‐ ing and to optimize the data analysis methods presented in the scientific article “Predictors of failure with high‐flow nasal oxygen therapy in COVID‐19 patients with acute respiratory failure: a multicen‐ ter observational study”[13]. Furthermore, it provides a predictive model of mortality. The study is centered around a COVID‐19 patient database that have gone through High Flow Nasal Oxygena‐ tion (HFNO) therapy, intending to create a predictive model with the ability to infer the necessity of invasive intubation once the initial clinical conditions are known during patient ICU admission. To de‐ velop this model, data was collected from 5 hospitals in Spain and Andorra during the initial stages of the COVID‐19 pandemic. From this process, a database of 1129 patients was obtained, from which 259 received HFNO. With the goal of mining this database, this project analyzes these patients to develop two models to estimate the probability of intubation and mortality. Therefore, an efficient methodology to quickly test and validate various machine learning algorithms is developed. The methods used to obtain this new mortality model are applicable to other output variables. Hence, an alternative model to predict intubation is also developed. The results obtained from this new model are comparable to the previous study [13], and also provide viable alternatives to enhance the development of tools to help the medical community in the decision‐making process based on machine learning technologies. Furthermore, it opens new possibilities where the knowledge from information processing can provide solutions to real and urgent necessities of society

Covered Interest Rate Parity

The idea of covered interest rate parity (CIP) states that simultaneous purchase and sale of two currencies should not result in profit. This parity condition is examined using error correction model (ECM), descriptive analysis of profitable deviations and impulse response functions from the vector error correction model (VECM). This study on average finds support for the parity condition. However, there is also evidence for some rare but large deviations. Majority of the profitable deviations are small in size. Results for persistence of the profitable deviations are mixed. These results suggests that there is not sufficient evidence for either accepting or rejecting the CIP and efficiency of the market. Thus, this paper is inconclusive regarding the validity of CIP and efficiency of the market.Master i okonomi og administrasjo

ANN for English Alphabet Prediction

Abstract: In this paper an Artificial Neural Network (ANN) model, for predicting the Letters from twenty dissimilar fonts for each letter. The character images were, initially, based on twenty dissimilar fonts and each letter inside these twenty fonts was arbitrarily distorted to yield a file of 20,000 distinctive stimuli. Every stimulus was transformed into 16 simple numerical attributes (arithmetical moments and edge amounts) which were then ascended to be suitable into a range of numeral values from 0 to 15. We naturally chose, arbitrarily, 1,000 distinctive stimuli for this research. We made certain that the scattering remnants the similar after selecting the one thousand stimuli. In this research, a neural network tool (Just NN) was used for the purpose of predicting to classify every of a huge number of black and white four-sided pixel displays as one of the 26 capital letters in the English language

Chronic Hepatitis B, C, And Stroke; Association and Pathophysiology

Background and Objectives: Hepatitis infection may raise the incidence of stroke and other cerebrovascular abnormalities, according to several studies. However, its association is controversial. This review looked to compile the most recent research on the relationship between HBV and HCV, atherosclerosis, and stroke. Methods:This article reviews the literature on the connection between hepatitis B and C viruses with stroke and atherosclerosis. The search included articles from PubMed, PakMediNet, and Google Scholar, as well as a Medline search using specific keywords and MeSH terms. A total of 2655 articles were identified. Out of these 2655 articles we identified 134 articles in English for review. These 134 articles comprised of original studies, individual case studies, and retrospective cohorts. The review included original research, individual case reports, and retrospective cohorts published after 1990. Studies addressing co-infection with HIV were excluded. Results:After the screening, many articles were selected which included several topics of discussion under the said heading. The studies were closely examined to gather pertinent information relevant to the review\u27s objectives. Most of the literature emphasized the link between chronic hepatitis and the risk of stroke. Conclusion: Although current evidence does tilt the scale in favor of hepatitis-causing cerebrovascular disease, this review study has some limitations, such as the lack of prospective cohorts and limited evidence for the natural history of hepatitis patients in relation to cardiovascular and cerebrovascular diseases

Perspektif para kiai tentang Pinjaman Dana Bergulir di Unit Pengelola Kegiatan (UPK) dalam Program Pemberdayaan Masyarakat Mandiri Pedesaan (PNPM-MP) di Desa Batah Timur Kec. Kwanyar Kab. BangkalanL: studi hukum Islam

Skripsi ini merupakan hasil penelitian lapangan yang bertujuan untuk menjawab pertanyaan bagaimana praktik pinjaman dana bergulir, bagaimana perspektif para kiai tentang pinjaman dana bergulir dan bagaimana analisis hukum Islam terhadap perspektif kiai setempat tentang pinjaman dana bergulir di UPK (Unit Pengelola Kegiatan) dalam Program Nasional Pemberdayaan Masyarakat Mandiri Pedesaan (PNPM-MP) di desa Batah Timur Kec. Kwanyar Kab. Bangkalan. Dalam penelitian ini teknik yang digunakan adalah diskriptif analisis yaitu menggambaran peristiwa yang berhubungan dengan masalah kemudian menganalisisnya dengan menggunakan landasan teori yang ada dengan menggunakan pola pikir induktif yakni berangkat dari fakta-fakta yang khusus, kemudian ditarik kesimpulan yang bersifat umum. Hasil yang ditemukan adalah pertama, program dana bergulir Unit Pengelola Kegiatan (UPK) merupakan dana pinjaman secara berkelompok dimana perhitungan keuntungannya (bunga) adalah dihltwig dari persentase pinjaman pokoknya, kedua, Kiai Achmad Nahrowi Shodiq dan Ustad Zainal Abidin memperbolehkan pinjaman dana bergulir di Unit Pengelola Kegiatan (UPK) dengan alasan karena maslahatnya lebih banyak daripada madharatnya sedangkan Kiai Haji Abdullah tidak memperbolehkan dengan alasan praktek simpan pinjam dana bergulir di UPK Kwanyar Desa Batah Timur termasuk riba karena adanya penambahan harta dalam pengembalian utang (pinjaman). Kctiga, Wahbah az­Zuhaili mengkaji hukum bunga bank melalui riba dalam terminologi ulama-ulama klasik dalam berbagai mazhab fiqih klasik, maka keuntungan dalam pinjaman dana bergulir di UPK termasuk riba nasi'ah. Perspektif tersebut berbeda dengan perspektif beberapa fuqaha kontemporer, diantaranya Ahmad Hasan (pendiri Persis), organisasi Islam Nahdhatul Ulama Indonesia, Abdul Hamid Hakim (tokoh pembaharu dari Sumatera Barat), Syafruddin Prawiranegara (tokoh Masyumi), Muhammad Quraish Shihab menyimpulkan keuntungan dalam pinjaman dana bergulir UPK itu dibolehkan atau halal dengan pertimbangan maslahat atau manfaat yang ditimbulkan lebih banyak daripada madharatnya. Karena 'illat dari keharaman riba itu adalah adanya sifat aniaya (az-zulm) dan hal tersebut tidak terdapat dalam pinjaman dana bergulir UPK, di dalam perjanjian di UPK juga terdapat unsm kerelaan dalam pembagian keuntungan karena dalam perjanjian antara pihak peminjam dan UPK terlebih dahulu dimusyawarahkan dalam forum MAD (Masyarakat Antar desa). Sejalan dengan kesimpulan diatas demi tercapainya tujuan yang maksimal terhadap program nasional yang sifatnya sosial maka peran kiai sebagai aparat penasehat di desa lebih dimaksimalkan sehingga realisasi program nasional tersebut tidak menyimpang dari nilai­nilai Syariah

Exploring Noise Pollution, Causes, Effects, and Mitigation Strategies: A Review Paper

Noise pollution, often regarded as a silent menace amidst the clamor of more conspicuous environmental concerns, is a pervasive and escalating issue with profound implications for humanity and the natural world. This comprehensive review paper delves into the multifaceted realm of noise pollution, encompassing its diverse causes, far-reaching effects, and the array of strategies deployed to mitigate its adverse consequences. Within this paper, we embark on an exploration that begins by scrutinizing the intricate tapestry of noise pollution's origins. We dissect the urban sprawl and infrastructure development that spawns construction-related tumult, the transportation networks that propagate incessant road, air, and rail noise, and the industrial activities that generate relentless auditory dissonance. These sources collectively converge to create a symphony of cacophony that increasingly defines modern existence. The effects of noise pollution extend beyond mere annoyance. We scrutinize its deleterious impact on human health, from sleep disturbances and cardiovascular diseases to cognitive impairments and stress-related disorders. We unravel the psychological ramifications, including reduced cognitive performance, annoyance, and social isolation. Furthermore, we delve into its insidious intrusion into the natural world, disrupting wildlife behavior, habitats, and reproductive success. Noise pollution also exerts socio-economic repercussions, diminishing property values and impairing learning environments. Mitigation strategies emerge as our beacon of hope. Regulatory measures, noise barriers, urban planning, technological innovations, public awareness campaigns, and international cooperation collectively form our arsenal in the battle against noise pollution. By recognizing noise pollution as an environmental challenge with profound ramifications and by collectively deploying these strategies, we aspire to cultivate a quieter, healthier, and more harmonious world for present and future generations, echoing a harmonious symphony of coexistence amidst the urban bustle

The impact of virtual tools on EFL learners’ performance in Grammar at the times of COVID 19 Pandemic

The main objective of this study is to investigate the impact of virtual tools on EFL learners’ performance in grammar courses during the COVID-19 pandemic. This experimental study compared a group of students who took a grammar course remotely via the Blackboard platform during the COVID-19 pandemic to a control group who took the same course in person prior to the pandemic. Each group of participants (n = 30) was given the same test. The grades of the two groups were then analysed using the SPSS programme. The results demonstrate that the experimental group test grades were higher than those of the control group grades. suggesting that teaching grammar remotely has a positive influence on EFL learners\u27 performance, as compared to face-to-face instruction, which has been proven to have a lesser impact. As a result, the researchers would promote a hybrid of virtual and face-to-face teaching. As a result, the researchers would promote a hybrid of virtual and face-to-face teaching. More studies on the causes of lower grades in face-to-face classes, as well as suggestions for strategies to improve learners\u27 performance in all aspects of the English language, not just grammar, are requested. Furthermore, each country has its own educational policy, so different results may arise in different contexts. Educators and policymakers may use this study as a reference for the effectiveness of virtual vs. face-to-face instruction, opening the doors for future research on similar topics within the same them