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Abstrak :
Di masa kini, keamanan bahan pangan telah menjadi salah satu fokus utama bagi seluruh komponen sektor pangan, karena meningkatnya kesadaran masyarakat akan makanan yang aman, lezat, dan sehat. Patogen asing dan mikroorganisme pengurai merupakan mikroorganisme yang paling bertanggung jawab atas wabah penyakit yang ditularkan melalui makanan. Terdapat beberapa teknik termal konvensional yang dapat digunakan untuk membasmi mikroorganisme ini, seperti pasteurisasi, sterilisasi, pemanasan ohmik, autoklaf, dll. Namun, teknik-teknik ini semakin kurang diminati di pasaran, karena penerapan panas yang sangat tinggi berdampak buruk pada atribut kualitas fisiko-kimia, nutrisi, dan sensorik dari makanan yang diolah. Oleh sebab itu, berbagai teknologi alternatif non-termal telah dikembangkan dan dipelajari untuk memperoleh bahan pangan yang tetap aman dengan minimnya penggunaan bahan pengawet dan bebas bahan kimia, namun tetap mempertahankan sifat alaminya seperti kualitas sensorik dan gizi dalam waktu yang lama. Sebagai solusi alternatif, salah satunya dapat digunakan Plasma Activated Water (PAW). Metode generasi PAW yang optimal dan sering digunakan adalah Dielectric Barrier Discharge (DBD), karena efisiensinya dalam menghasilkan plasma dan kemudahan pengaplikasiannya dalam skala besar. Pada penelitian ini, akan dicipatakan Plasma Activated Water (PAW) menggunakan metode produksi Dielectric Barrier Discharge (DBD) dengan alat Ozone Generator. Agar sesuai dengan perkembangan zaman, maka peralatan Ozone Generator ini dicoba dilengkapi dengan sistem nyala-mati otomatis, agar campur tangan manusia dapat diminimalisir dalam pengendalian sistem sebisa mungkin. Dari percobaan, diukur parameter pH, konduktivitas, dan tingkatan ORP, dengan memerhatikan perkembangan parameter tersebut berdasarkan variasi percobaan volume air 100 mL, 200 mL, dan 300 mL, dan waktu treatment 1 menit, 3 menit, dan 5 menit. Hasil perkembangan parameter yang diukur diperoleh sudah sesuai dengan karakteristik terbentuknya PAW, yang ditemukan pada berbagai jurnal ilmiah yang meneliti karakteristik fisikokimiawi pada PAW. Sehingga, dapat dikatakan sistem Plasma Generator sederhana ini berhasil memproduksi PAW, dimana dengan parameter-parameter yang berhasil diukur, memiliki potensi untuk menjaga berbagai kualitas fisikokimia, sensorik, dan nutrisi pada bahan pangan lebih tahan lama. ......Nowadays, food safety has become one of the main focuses for all components of the food sector, due to increasing public awareness of safe, delicious and healthy food. Foreign pathogens and decomposing microorganisms are the microorganisms most responsible for food-borne disease outbreaks. There are several conventional thermal techniques that can be used to eradicate these microorganisms, such as pasteurization, sterilization, ohmic heating, autoclaving, etc. However, these techniques are becoming less popular on the market, as the application of very high heat has an adverse impact on the physico-chemical, nutritional and sensory quality attributes of the processed food. For this reason, various alternative non-thermal technologies have been developed and studied to obtain food ingredients that remain safe with minimal use of preservatives and are free of chemicals, but still maintain their natural properties such as sensory and nutritional qualities for a long time. As an alternative solution, one of them can be used Plasma Activated Water (PAW). The optimal and frequently used PAW generation method is Dielectric Barrier Discharge (DBD), because of its efficiency in producing plasma and ease of application on a large scale. In this research, Plasma Activated Water (PAW) will be created using the Dielectric Barrier Discharge (DBD) production method with an Ozone Generator. In order to be in line with current developments, the Ozone Generator equipment has been tried to be equipped with an automatic on-off system, so that human intervention can be minimized in controlling the system as much as possible. From the experiment, the parameters pH, conductivity, and ORP level were measured, by paying attention to the development of these parameters based on experimental variations in water volumes of 100 mL, 200 mL, and 300 mL, and treatment times of 1 minute, 3 minutes, and 5 minutes. The results of the development of the measured parameters were found to be in accordance with the characteristics of PAW formation, which were found in various scientific journals that examined the physicochemical characteristics of PAW. So, it can be said that this simple Plasma Generator system has succeeded in producing PAW, which, with the parameters that have been successfully measured, has the potential to maintain various physicochemical, sensory and nutritional qualities in foodstuffs that last longer.

Abstrak :
In recent developments in the area of thermofluid technologies, active flow control has emerged as an interesting topic of research. One of the latest methods, which will be discussed in this paper, is the application of a plasma actuator. Plasma actuation is achieved by conducting a high-voltage electric current through an actuator device. Our research was specifically conducted to discover its effect on the reduction of the drag coefficient, with Ahmed Body the experimental object put inside a suction-flow wind tunnel with varying inputs of flow velocity. The plasma actuator device was run with an A.C. power supply and installed in three different placement configurations on the aerodynamic model to determine which most optimally affected the aerodynamic drag, while the drag coefficients were acquired via the use of a load cell installed as the harness for the aerodynamic model inside the tunnel. The results of the experiments include that the optimal configuration of the actuator placement was on the leading edge, the optimal wind flow velocity of the experiment, which was essential for the actuation to be observed, was at 1.7 m/s, and the resulting drag reduction percentage, as a result of induced flow, was 22% of the initial drag coefficient.

Abstrak :
Salah satu terapi COVID-19 adalah plasma konvalesen yang disiapkan Unit Transfusi Darah dari donor yang telah sembuh dari COVID-19. Plasma konvalesen mengandung antibodi netralisasi yang menghambat interaksi antara protein S dengan reseptor ACE2 dengan persyaratan minimal titer 1:160 sehingga diperlukan sistem deteksi antibodi netralisasi seperti tes serologi berbasis ELISA kompetitif yang mudah, murah, cepat dan tidak membutuhkan BSL 3 atau 2. Uji ini membutuhkan protein rekombinan spike S1 yang dapat diekspresikan pada sistem ekspresi mamalia. Penelitian ini bertujuan untuk mendeteksi antibodi spesifik SARS-CoV-2 pada plasma konvalesen COVID-19 menggunakan protein rekombinan Spike S1.Penelitian ini menggunakan plasmid pD609 sebagai vektor ekspresi yang terdapat gen spike S1. DNA ditransfeksi secara transien ke sel CHO. Immunostaining dilakukan setelah transfeksi untuk melihat ekspresi protein rekombinan spike S1 pada sel CHO. Supernatan media sel CHO post transfeksi dianalisis dengan western blot dan ELISA untuk melihat reaktifitas terhadap serum konvalesen COVID-19. Hasil immunostaining menunjukkan plasmid pD609 S1 Spike Foldon-His dapat mengekspresikan protein rekombinan spike S1 SARS-CoV-2 pada sel CHO. Hasil Western Blot dan ELISA menunjukkan supernatan media sel kultur CHO post transfeksi reaktif terhadap serum konvalesen COVID-19. Protein rekombinan spike S1 memiliki potensi untuk dikembangkan dan digunakan dalam uji antibodi spesifik namun hasil ekspresi protein masih rendah. ......One of the therapies for COVID-19 is convalescent plasma prepared by the Blood Transfusion Unit from donors who have recovered from COVID-19. Convalescent plasma contains neutralizing antibodies that inhibit the interaction between S protein and ACE2 receptors with a minimum requirement of a titer of 1:160 so that a neutalizing antibody detection system is needed such as a competitive ELISA-based serological test that is easy, inexpensive, fast, and does not require BSL 3 or 2. S1 spike recombinant protein that can be expressed in mammalian expression systems. This study aims to detect SARS-CoV-2 specific antibodies in COVID-19 convalescent plasma using recombinant Spike S1 protein. This study used the pD609 plasmid as an expression vector containing the spike S1 gene. DNA was transiently transfected into CHO cells. Immunostaining was performed after transfection to see the expression of the S1 spike recombinant protein in CHO cells. The post-transfected CHO cell media supernatans were analyzed by western blot and ELISA to see the reactivity to COVID19 convalescent serum. Immunostaining results showed that the plasmid pD609 S1 Spike Foldon-His could express the SARS-CoV-2 spike S1 recombinant protein in CHO cells. The results of Western blot and ELISA showed that the post-transfection CHO cell culture media supernatant was reactive to COVID-19 convalescent serum. S1 spike recombinant protein has the potential to be developed and used in specific antibody assays, but the results of protein expression is still low.

Abstrak :
Amonia diproduksi menggunakan proses Haber-Bosch yang menghasilkan emisi tinggi, maka diperlukan alternatif yang ramah lingkungan. Elektrolisis plasma dengan injeksi udara menghasilkan radikal •N melalui injeksi udara dan radikal •H dalam larutan elektrolit. Elektrolisis plasma juga membentuk nitrat karena radikal •OH akibat keberadaan oksigen dalam udara. Penelitian ini bertujuan untuk mengetahui pengaruh pemilihan plasma anodik dan katodik, keberadaan gas oksigen, laju alir injeksi udara, dan pH awal larutan dalam reaktor serta trap cell terhadap produksi amonium dan nitrat dengan teknologi elektrolisis plasma. Penelitian ini menggunakan aditif metanol, elektrolit Na2SO4 dengan konsentrasi 0,02 M, dan sebuah penangkap gas. Hasil produksi amonium dan nitrat diukur konsentrasinya dengan metode spektroskopi UV-Vis. Penelitian ini menghasilkan amonium terbanyak menggunakan elektrolisis plasma katodik (550 V), laju alir udara 0,8 lpm, dan pH awal larutan elektrolit dan trap cell sebesar 3. Kondisi tersebut memproduksi 2,57 mmol amonium, 10,94 mmol nitrat, energi spesifik 578,6 kJ/mmol, dan ketergerusan elektroda sebesar 0,27 gram. ......Ammonia is produced using Haber-Bosch process which produces high emissions, so an environmentally friendly alternative is needed. Air plasma electrolysis produces •N radicals through air injection and •H radicals in an electrolyte solution. Plasma electrolysis forms nitrate because •OH radicals due to the oxygen presence in the air. This study aims to determine the effect of anodic and cathodic plasma selection, the presence of oxygen gas, air injection flow rate, and initial pH of electrolyte solution and trap cell solution to the ammonium and nitrate production using plasma electrolysis. This study uses methanol additive, Na2SO4 electrolyte with concentration of 0.02 M, and a trap cell. Produced ammonium and nitrate concentration was measured using UV-Vis spectrophotometer. This study produced highest ammonium using cathodic plasma electrolysis (550 V), air flow rate of 0.8 lpm, and initial pH of electrolyte solution and trap cell of 3. These conditions produced 2.57 mmol ammonium, 10.94 mmol nitrate, specific energy 578.6 kJ/mmol, and electrode erodibility of 0.27 gram.