EFFECTS OF KAOLIN CONCENTRATION AS FILLER ON VULCANIZATION OF RUBBER YARNS

Abstract. A study has been conducted by mixing kaolin and titanium dioxide (TiO2) used as a filler on latex compounds which have been concentrated in the manufacture of rubber yarns with kaolin variations of 0; 6; 12; 15. This research was conducted to find out the result of kaolin concentration effects on rubber yarns vulcanization. The results showed that the concentration of kaolin mixed with titanium dioxide (TiO2) affect on rubber yarns vulcanization. The higher the concentration kaolin the smaller the swelling, so the time of vulcanization will take longer.Keywords: Kaolin, Rubber Yarns, and Vulcanizatio

MECHANICAL PROPERTIES OF RUBBER YARN WITH THE ADDITION OF KAOLIN AS A REINFORCING FILLER

Rubber yarns have been made using kaolin and titanium dioxide (TiO2) as fillers on concentrated latex compounds, with kaolin variations of 0, 6, 12, and 15 phr. This research was conducted to find out the result of kaolin concentration analysis on rubber vulcanization. The observed mechanical properties include a modulus of 300%, a modulus of 500%, a breaking tension, and a breaking extension. Kaolin mixed with titanium dioxide (TiO2) has an effect on the mechanical properties of rubber yarn. The higher the kaolin concentration, the mechanical properties of the rubber yarn are getting worse, as it is increasingly away from the standard value set for the rubber yarn.Keywords: Kaolin, rubber yarn, and vulcanization

PENGARUH BAHAN ELEKTRODA TERHADAP KELISTRIKAN BELIMBING WULUH (AVERRHOA BILIMBI) SEBAGAI SOLUSI ENERGI ALTERNATIF RAMAH LINGKUNGAN

Penelitian ini bertujuan untuk menghasilkan baterai aki basah yang ramah lingkungan denganmemanfaatkan belimbing wuluh (Averrhoa Bilimbi) sebagai elektrolit dan beberapa logamsebagai pasangan elektroda. Sehingga selain dapat memenuhi kebutuhan energi listrik yangsangat tinggi, penelitian ini juga dapat menjadi salah satu solusi dalam mengatasi masalahdalam produksi energi listrik yang selama ini memberikan kontribusi sangat besar terhadapemisi gas rumah kaca.Metode yang digunakan adalah metode eksperimen yang dilakukan diLaboratorium Fisika UMN Al Washliyah. Elektrolit belimbing wuluh (Averrhoa Bilimbi)terlebih dahulu di ekstrak dan disaring dengan filter nomor 40. Pasangan Elektroda (anoda dankatoda) yang digunakan pada penelitian ini yaitu: tembaga:seng; tembaga:aluminium;tembaga:besi; dan tembaga:timah. Masing–masing plat elektroda dipotong dengan ukuran 4,5 x10 cm. Dibuat bak untuk prototipe baterai, dan disusun rangkaian dengan variasi dari masingmasingpasanganelektroda.Untukmengetahuipengaruhdarivariasisetiappasanganelektroda dilakukan pengukuran tegangan dan arus dengan hambatan 5 ohm, sehingga dapat diketahuipasangan elektroda terbaik dalam pemanfaatan belimbing wuluh (Averrhoa Bilimbi) sebagaielektrolit dalam pembuatan baterai aki basah. Hasil pengukuran PH larutan belimbing wuluhsebesar 1,6. Hasil pengujian dengan beberapa pasangan elektroda pada biobaterai, semua lampuLED menyala dan terdapat gelembung gas pada larutan elektrolit, hal ini membuktikan bahwalarutan belimbing wuluh termasuk asam kuat, sehingga merupakan senyawa elektoril kuat. Padapasangan elektroda tembaga-seng nilai tegangannya lebih tinggi dari pasangan elektroda yanglain yaitu sebesar 3 volt dan ini berbanding lurus dengan nilai kuat arus yang dihasilkan sebesar0,6 amper, sedangkan besar tegangan yang paling kecil dihasilkan oleh pasangan elektrodatembaga-timah sebesar 1,5 volt dan kuat arus sebesar 0,3 amper. Hal ini terjadi karena reaksiantara unsur penyusun pasangan logam sebagai elektroda dengan larutan belimbing wuluhsebagai elektrolit. Besar tegangan dan kuat arus yang dihasilkan pada penelitian ini jugatergantung dengan jumlah volume larutan, jumlah pasangan elektroda dan rangkaian yangdigunakan, tetapi dengan perbandingan hasil yang sama. &nbsp

ERROR ANALYSIS OF USING AUXILIARY VERBS IN WRITING DESCRIPTIVE TEXT

Grammar is complexity in learning English it makes many students often commit errors in learning. Making errors in writing is one of the processes for learning English .The aim of this research was to describe the students’ errors and its causes in using auxiliary verbs in the sentences. In this research, the writer limited the discussion on the error made by the students in using auxiliary verbs. The design of this research was quantitative approach in a form of descriptive analysis (percentage) that included observation, collecting the data the researcher used test as the instrument. The writer conducted the research to 31 students in first semester of English Literature in academic 2021/2022. The data were analyzed by using error analysis method. The error types were classified based on linguistic category, especially surface strategy taxonomy. The writer classified the types of error into omission, addition, misformation, and misordering. Among those four types, the most frequency error was misformation  that reached 102 errors or 61.44% . the other finding was the sources of error which are divided into three categories. Those are interlingual errors, intralingual errors, and communicative strategies. Communicative strategies errors is the most common source of error, there were 45.78

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes.

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne

ANALYSIS STUDY THROUGH MATHEMATICA 5.1 SIMULATION PROGRAM IN DETERMINING THE DENSITY AND POROSITY OF CORDIERITE CERAMICS

The research conducted was an experiment with a computational simulation design using the Wolfram Mathematica 5.1 program to view and analyze physical characteristics (density and porosity) of Cordierite Ceramics. The involvement of advanced computers in research will connect the theories and experiments that have been accepted as one of the methods of material research and development. The research variables in this simulation are sintering temperatures of 1200, 1250, 1300, and 1350 °C mixed with wood powder by 20% by weight. The parameters of this study are density and porosity. The simulation results show that with a composition of 20% wood powder and sintering temperature of 1300 °C the density values of 0.97 g/cm3 and porosity of 60.11% are the best conditions that are close to the literature. By comparing the results of simulations and experiments, it can be concluded that through simulation analysis of density and porosity, constant changes can be obtained due to a constant increase in sintering temperature and it can also be analyzed with a smaller temperature increase interval.Keywords: Cordierite Ceramics, Density, Porosity, and Wolfram Mathematica

The mPEG-PCL Copolymer for Selective Fermentation of Staphylococcus lugdunensis Against Candida parapsilosis in the Human Microbiome.

Many human skin diseases, such as seborrheic dermatitis, potentially occur due to the over-growth of fungi. It remains a challenge to develop fungicides with a lower risk of generating resistant fungi and non-specifically killing commensal microbes. Our probiotic approaches using a selective fermentation initiator of skin commensal bacteria, fermentation metabolites or their derivatives provide novel therapeutics to rein in the over-growth of fungi. Staphylococcus lugdunensis (S. lugdunensis) bacteria and Candida parapsilosis (C. parapsilosis) fungi coexist in the scalp microbiome. S. lugdunensis interfered with the growth of C. parapsilosis via fermentation. A methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-PCL) copolymer functioned as a selective fermentation initiator of S. lugdunensis, selectively triggering the S. lugdunensis fermentation to produce acetic and isovaleric acids. The acetic acid and its pro-drug diethyleneglycol diacetate (Ac-DEG-Ac) effectively suppressed the growth of C. parapsilosis in vitro and impeded the fungal expansion in the human dandruff. We demonstrate for the first time that S. lugdunensis is a skin probiotic bacterium that can exploit mPEG-PCL to yield fungicidal short-chain fatty acids (SCFAs). The concept of bacterial fermentation as a part of skin immunity to re-balance the dysbiotic microbiome warrants a novel avenue for studying the probiotic function of the skin microbiome in promoting health

PEG-8 Laurate Fermentation of Staphylococcus epidermidis Reduces the Required Dose of Clindamycin Against Cutibacterium acnes

The probiotic activity of skin Staphylococcus epidermidis (S. epidermidis) bacteria can elicit diverse biological functions via the fermentation of various carbon sources. Here, we found that polyethylene glycol (PEG)-8 Laurate, a carbon-rich molecule, can selectively induce the fermentation of S. epidermidis, not Cutibacterium acnes (C. acnes), a bacterium associated with acne vulgaris. The PEG-8 Laurate fermentation of S. epidermidis remarkably diminished the growth of C. acnes and the C. acnes-induced production of pro-inflammatory macrophage-inflammatory protein 2 (MIP-2) cytokines in mice. Fermentation media enhanced the anti-C. acnes activity of a low dose (0.1%) clindamycin, a prescription antibiotic commonly used to treat acne vulgaris, in terms of the suppression of C. acnes colonization and MIP-2 production. Furthermore, PEG-8 Laurate fermentation of S. epidermidis boosted the activity of 0.1% clindamycin to reduce the sizes of C. acnes colonies. Our results demonstrated, for the first time, that the PEG-8 Laurate fermentation of S. epidermidis displayed the adjuvant effect on promoting the efficacy of low-dose clindamycin against C. acnes. Targeting C. acnes by lowering the required doses of antibiotics may avoid the risk of creating drug-resistant C. acnes and maintain the bacterial homeostasis in the skin microbiome, leading to a novel modality for the antibiotic treatment of acne vulgaris

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes.

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne