The impact of year-to-year changes in the weather on the seasonal dynamics of lakes

The methods currently used to monitor and model lakes were developed when weather conditions were very different to what they are today. Most are based on samples collected at weekly or fortnightly intervals and cannot quantify the effects of short-term, more extreme, variations in the weather. In this article, the author presents some examples to show the importance of developing new monitoring methods using case studies from a number of lakes in the English Lake District. The impact of year-to-year changes and short-term changes on the dynamics of of lakes are highlighted

Evolution of planetesimal velocities

A self-consistent set of equations for the velocity evolution of a general planetesimal population is presented. The equations are given in a form convenient for calculations of the early stages of planetary accumulation when it is necessary to model the planetesimal swarm by methods of gas dynamics, rather than follow the orbital evolution of individual bodies. Steady state velocities of a simple planetesimal population consisting of two different sizes of bodies are calculated. Dynamical friction is found to be an important mechanism for transferring kinetic energy from the larger planetesimals to the smaller ones. When the small planetesimals are relatively abundant, gas drag and inelastic collisions among the smaller bodies are of comparable importance for dissipating energy from the population

PERENCANAAN STRATEGIS DALAM PENGEMBANGAN POTENSI PARIWISATA KABUPATEN KEPULAUAN YAPEN

Tujuan: Penelitian ini bertujuan untuk mengetahui dan menganalisis kekuatan, kelemahan, peluang dan ancaman, mengetahui kondisi lingkungan internal dan eksternal serta strategi yang tepat untuk mengembangkan potensi wisata di Kabupaten Kepulauan Yapen.Metode: Penelitian ini dilakukan dengan cara survey dan pengolahan data penelitian ini menggunakan teknik analisis statistic deskriptif dan analisis formulasi strategi.Hasil: Hasil penelitian yang diperoleh adalah pada analisis lingkungan yaitu lingkungan internal dan eksternal serta alternative strategi yang diberikan. Analisis lingkungan internal menunjukkan bahwa faktor kunci internal dari Kabupaten Kepulauan Yapen yaitu kekuatan (1) struktur organisasi yang jelas, (2) mempunyai pembiayaan yang cukup untuk kelancaran tugas karyawan, (3) Sarana dan prasarana cukup memadai, (4) Mempunyai website, (5) Mempunyai daya tarik alam dan bahari, (6) Mempunyai SDM di bidang akuntansi yang handal . Dan kelemahan (1) Kurangnya infrastruktur menuju ke destinasi, (2) Masyarakat kurang ramah ke wisatawan, (3) Terjadi kasus pencurian, (4) Kurangnya SDM untuk mengelola tempat wisata, (5) Promosi masih kurang maksimal. Analisis lingkungan eksternal menunjukkan bahwa faktor kunci eksternal yaitu berupa peluang (1) Investasi yang bagus, (2) Mempunyai perhatian dari pemerintah pusat, (3) Mempunyai daya tarik berbeda dengan wisata di Papua, (4) Website yang bisa dijadikan alat promosi. Dan ancaman (1) Banyaknya objek wisata sejenis, (2) Perekonomian kurang stabil, (3) Faktor keamanan belum kodusif, (4) Ditutupnya wisata di Indonesia karena Covid-19. Adapun urutan prioritas strategi yang dapat diterapkan di Kabupaten Kepulauan Yapen, yaitu pengembangan produk yaitu dengan peningkatan daya tarik wisata dengan menambah fasilitas, memanfaatkan kearifan lokal menjadi sarana rekreasi edukasi, perbaikan infrastruktur, penetrasi pasar yaitu dengan membuat akun media sosial dan membuat iklan di media sosial, integrasi ke belakang yaitu dengan selalu memperbaharui website dan integrasi ke depan yaitu dengan memberikan paket wisata lebih murah saat mengajak orang lain

PERENCANAAN STRATEGIS DALAM PENGEMBANGAN POTENSI PARIWISATA KABUPATEN KEPULAUAN YAPEN

Tujuan: Penelitian ini bertujuan untuk mengetahui dan menganalisis kekuatan, kelemahan, peluang dan ancaman, mengetahui kondisi lingkungan internal dan eksternal serta strategi yang tepat untuk mengembangkan potensi wisata di Kabupaten Kepulauan Yapen.Metode: Penelitian ini dilakukan dengan cara survey dan pengolahan data penelitian ini menggunakan teknik analisis statistic deskriptif dan analisis formulasi strategi.Hasil: Hasil penelitian yang diperoleh adalah pada analisis lingkungan yaitu lingkungan internal dan eksternal serta alternative strategi yang diberikan. Analisis lingkungan internal menunjukkan bahwa faktor kunci internal dari Kabupaten Kepulauan Yapen yaitu kekuatan (1) struktur organisasi yang jelas, (2) mempunyai pembiayaan yang cukup untuk kelancaran tugas karyawan, (3) Sarana dan prasarana cukup memadai, (4) Mempunyai website, (5) Mempunyai daya tarik alam dan bahari, (6) Mempunyai SDM di bidang akuntansi yang handal . Dan kelemahan (1) Kurangnya infrastruktur menuju ke destinasi, (2) Masyarakat kurang ramah ke wisatawan, (3) Terjadi kasus pencurian, (4) Kurangnya SDM untuk mengelola tempat wisata, (5) Promosi masih kurang maksimal. Analisis lingkungan eksternal menunjukkan bahwa faktor kunci eksternal yaitu berupa peluang (1) Investasi yang bagus, (2) Mempunyai perhatian dari pemerintah pusat, (3) Mempunyai daya tarik berbeda dengan wisata di Papua, (4) Website yang bisa dijadikan alat promosi. Dan ancaman (1) Banyaknya objek wisata sejenis, (2) Perekonomian kurang stabil, (3) Faktor keamanan belum kodusif, (4) Ditutupnya wisata di Indonesia karena Covid-19. Adapun urutan prioritas strategi yang dapat diterapkan di Kabupaten Kepulauan Yapen, yaitu pengembangan produk yaitu dengan peningkatan daya tarik wisata dengan menambah fasilitas, memanfaatkan kearifan lokal menjadi sarana rekreasi edukasi, perbaikan infrastruktur, penetrasi pasar yaitu dengan membuat akun media sosial dan membuat iklan di media sosial, integrasi ke belakang yaitu dengan selalu memperbaharui website dan integrasi ke depan yaitu dengan memberikan paket wisata lebih murah saat mengajak orang lain

Marshallian VS. Walrasian Stability in an Experimental Market

Twelve markets were studied. All markets had downward sloping supply functions created by Marshallian-type external economics. The conditions were such that the Marshallian theory of dynamics gave predictions opposite to the Walrasian theory of dynamics. The market organizations studied were double auction, sealed bid/offer and (secant) tâtonnement. In all cases the Marshallian theory of dynamics was the better model

Practical quantum key distribution over a 48-km optical fiber network

The secure distribution of the secret random bit sequences known as "key" material, is an essential precursor to their use for the encryption and decryption of confidential communications. Quantum cryptography is a new technique for secure key distribution with single-photon transmissions: Heisenberg's uncertainty principle ensures that an adversary can neither successfully tap the key transmissions, nor evade detection (eavesdropping raises the key error rate above a threshold value). We have developed experimental quantum cryptography systems based on the transmission of non-orthogonal photon states to generate shared key material over multi-kilometer optical fiber paths and over line-of-sight links. In both cases, key material is built up using the transmission of a single-photon per bit of an initial secret random sequence. A quantum-mechanically random subset of this sequence is identified, becoming the key material after a data reconciliation stage with the sender. Here we report the most recent results of our optical fiber experiment in which we have performed quantum key distribution over a 48-km optical fiber network at Los Alamos using photon interference states with the B92 and BB84 quantum key distribution protocols.Comment: 13 pages, 7 figures, .pdf format submitted to Journal of Modern Optic

Marshallian vs. Walrasian Stability in an Experimental Market

The experiments discussed below are an attempt to examine concepts of stability as found in economic textbooks. Two concepts of stability, which stem from two different concepts of market adjustment, seem to have dominated thinking. Whilst these two concepts are typically called Walras stability and Marshall stability, some controversy exists over the extent to which these two models represent their respective thinking. No doubt the current formal statements of the theories reflect an evolution of the ideas through the work of many theorists. The terminology is retained for convenience. Regardless of their origins, these two concepts lead to competing hypotheses about the conditions under which market instability will be observed so the subject is a natural one for experimental investigation. Furthermore, since this is the first experimental examination of the stability of equilibria, the strategy is to inquire about stability in the context of these two classical models and to avoid the temptation to attempt to extend them or integrate them with more modern theory. The old models have not been checked. They seem to be an appropriate place to start

Pyrrolidine from N-alkyl-N-Chloroureas (Abstract)

Previous work in this laboratory has shown that when N-n-buty 1-N -chloro-p-toluenesulfonamide, N-n-butyl-N-chloroacetamide, or N-n-butyl-N-chloropropionamide is dissolved in sulfuric acid and heated, ring closure occurs with the formation of pyrrolidine in good yields. It was thought that N, N\u27-di-n-butyl-N, N\u27- dichlorourea might react in a similar manner. This was found to be the case. When this compound was dissolved in 95 per cent sulfuric acid and heated for a period of one hour at 120-130° C. pyrrolidine was formed in yields of 50 to 55 per cent. Under similar conditions N, N-dimethyl-N\u27-n-butyl-N\u27-chlorourea gave pyrrolidine in yields of 5 to 10 per cent