Penelitian ini bertujuan untuk mengetahui pengaruh keseimbangan, kekuatan otot tungkai, dan koordinasi terhadap ketepatan shooting. Metode penelitian yang digunakan dalam penelitian ini adalah  survei dengan teknik analisis jalur. Pengujian analisis dilakukan dengan perhitungan persyaratan data yaitu uji normalitas, uji signifikansi dan linieritas regresi. (1) Keseimbangan berpengaruh terhadap ketepatan shooting  dengan persamaan garis regresi linier Y = 8,904 + 0,474 X1, koefisien korelasi (rX1Y) = 0,349 dan koefisien determinasi (r2X1Y) =0,122 dan ρYX1 = 0,349, yang berarti variabel keseimbangan memberikan pengaruh langsung terhadap ketepatan shooting sebesar 12,22%. (2) Kekuatan otot tungkai berpengaruh terhadap ketepatan shooting  dengan persamaan garis regresi linier Y = 4,312 + 0,073 X2, koefisien korelasi (rX2Y) = 0,453 dan koefisien determinasi (r2X2Y) = 0,205 dan ρYX2 = 0,453, yang berarti variabel kekuatan otot tungkai memberikan pengaruh  langsung terhadap ketepatan shooting sebesar 20,5%. (3) Koordinasi berpengaruh terhadap ketepatan shooting dengan persamaan garis regresi linier Y = 10,073 + 0,412 X3, koefisien korelasi (rX3Y) = 0,294 dan koefisien determinasi (r2X3Y) = 0,086 dan ρYX3 = 0,294,  yang berarti variabel kekuatan otot tungkai memberikan pengaruh langsung terhadap ketepatan shooting. (4) Tidak ada pengaruh keseimbangan melalui koordinasi terhadap ketepatan shooting dengan nilai beta yaitu  0,251 (0,251 0,349). (5) Tidak ada pengaruh kekuatan otot tungkai melalui koordinasi terhadap ketepatan shooting dengan nilai beta yaitu 0,084 (0,084 0,453). AbstractThis study aims to determine the effect of balance, leg muscle strength, and coordination on the accuracy of shooting. The research method used in this study is a survey with path analysis techniques. Analysis testing is performed by calculating the data requirements namely normality test, significance test and linearity regression. (1) Balance affects the accuracy of shooting with the linear regression equation Y = 8.904 + 0.474 X1, the correlation coefficient (rX1Y) = 0.349 and the coefficient of determination (r2X1Y) = 0.122 and ρYX1 = 0.349, which means the balance variable gives a direct influence on the accuracy of shooting at 12.22%. (2) Leg muscle strength influences shooting accuracy with linear regression equation Y = 4.312 + 0.073 X2, the correlation coefficient (rX2Y) = 0.453 and the coefficient of determination (r2X2Y) = 0.205 and ρYX2 = 0.453, which means that the leg muscle strength variable gives an influence. directly to the shooting accuracy of 20.5%. (3) Coordination affects the accuracy of shooting with linear regression equation Y = 10.073 + 0.412 X3, the correlation coefficient (rX3Y) = 0.294 and the coefficient of determination (r2X3Y) = 0.086 and ρYX3 = 0.294, which means the leg muscle strength variable gives a direct influence on shooting accuracy. (4) There is no effect of balance through coordination on the accuracy of shooting with a beta value of 0.251 (0.251 0.349). (5) There is no effect of leg muscle strength through coordination on shooting accuracy with a beta value of 0.084 (0.084 0.453).

Penelitian ini bertujuan untuk menghasilkan model-model latihan groundstroke pada cabang olahraga tenis lapangan dengan menguji efektifitas terhadap latihan groundstroke pada cabang olahraga tenis lapangan dengan fokus usia atlet 14-16 tahun. Metode penelitian yang digunakan dalam penelitian ini yaitu metode penelitian dan pengembangan (Research and Development) dari Borg and Gall dengan menggunakan 10 tahapan. Subjek dalam penelitian ini melibatkan atlet usia 14-16 tahun. Rancangan item model divalidasi oleh 3 ahli pakar tenis lapangan yang terdiri dari 1 dosen tenis lapangan UNJ, 1 dosen biomekanika olahraga UNJ dan 1 pelatih tenis cibinong prestasi. Peningkatan latihan keterampilan groundstroke pada cabang olahraga tenis lapangan pada saat pre-test menunjukan signifikansi pada t-hitung= -8,718, df=19 dan p-value=0,00 0,05 artinya terdapat perbedaan yang signifikan pada model latihan keterampilan groundstroke sebelum dan sesudah diberikan perlakuan model latihan. Dapat disimpulkan bahwa model latihan keterampilan groundstroke yang dikembangkan efektif untuk meningkatkan latihan groundstroke untuk atlet atlet usia 14-16 tahun

Generally production of chitosan from crustacean shells consists of 4 steps, i.e. deproteinization, demineralization, decolorization and deacetylation. Simplification of chitosan production by elimination of deproteinization and/or demineralization, or reducing of reaction time would give many advantages, e.g. reduction of processing time and cost production due to reduction of chemical and power usage. The objectives of this research were to prepare chitosan under various processing times and to characterize the obtained chitin and chitosan. Chitin was prepared under various deproteinization times (0, 15, 30 min at 90 ºC using NaOH 2N) and demineralization times (0, 15, 30 min at ambient temperature using HCl 2N). Chitin was then bleached using aceton/etanol (1:1) for an hour. Deacetylation was achieved by treatment of chitin under condition at 120 ºC for 5 hr using NaOH 50%. Ash and nitrogen content, and degree of deacetylation of chitosan were evaluated. Demineralization and/or deproteinization times influenced the quality of chitin. Chitin and chitosan prepared without demineralization had white and chalky appearance, whereas the other chitosan were off-white in color. Ash and nitrogen contents of the chitosan products were 0.18 - 32.40% and 3.56 - 7.59%, respectively. Chitosan prepared under various processing times, except chitosan without demineralization treatment, had degree of deacetylation ≥ 70%.   Keywords: chitosan, deproteinization, demineralization, deacetylation, processing times

The lack of information regarding exercise program assessment tools during the COVID-19 pandemic was the main gap in this research. The purpose of this study was to investigate lecturers' perceptions of computer-based and paper pencil-based performance to assess sports training programs during the COVID-19 pandemic. In this study, a combination of quantitative and qualitative (mixed) is used as a method. Participants in this study were male and female lecturers from Jakarta State University (N=15) and Sriwijaya University (N=10). Quantitative instruments use questionnaires and qualitative instruments use in-depth interviews with participants. Quantitative data analysis use the IBM SPSS version 25.0 to find descriptive data, namely mean, standard deviation and percentage of responses from participation. Meanwhile, qualitative data analysis use qualitative thematic data. The results of the study based on quantitative data found that the majority of lecturers strongly agreed to use computer-based instead of paper pencil-based to assess sports training programs. Meanwhile, research results based on qualitative data show that most lecturers favour computer-based over paper pencil-based during the COVID-19 pandemic. Thus, computer-based has better performance and advantages than paper pencil-based when used in the pandemic era. This research provides benefits for the development of science assessment tools in the field of sports.

Penelitian dan pengembangan pada penelitian ini menggunakan instrumen angket, kuisioner, dan intrumen tes keterampilan gerak passing bawah bola voli yang digunakan untuk mengumpulkan data kuantitatif dan kualitatif. Penelitian dan pengembangan yang dilakukan peneliti mempunyai tahapan-tahapan yaitu: (1) analisis kebutuhan, (2) model produk berupa prototipe, (3) mengembangkan desain produk dan tahapan-tahapan pelaksanaan, (4) uji pakar ahli, (5) revisi, (6) uji lapangan lebih luas (7) revisi produk, (8) uji kelayakan, (9) produk final, (10) penyebaran secara luas. Uji keefektifitas melalui tes awal memperoleh nilai rata-rata sebesar 51,00 dan tes akhir memperoleh nilai rata-rata 72,05 maka dapat diambil kesimpulan bahwa model latihan passing bawah bola voli efektif untuk meningkatkan keterampilan gerak passing bawah. Berdasarkan hasil yang diperoleh dari uji efektifitas model maka dapat disimpulkan bahwa pengembangan model latihan passing bola voli yang telah diterapkan mengalami peningkatan, dibuktikan dengan tes awal dan tes akhir, adanya perbedaan yang signifikan dan dinyatakan layak untuk digunakan pada kegiatan latihan siswa sekolah menengah pertama. .