A vessel includes an engine; a first self-heat exchanger for heat-exchanging boil-off gas discharged from a storage tank; a multi-stage compressor for compressing, in multi-stages, the boil-off gas, which has passed through the first self-heat exchanger after being discharged from the storage tank; a first decompressor for expanding a portion of the boil-off gas, which has passed through the first self-heat exchanger after being compressed by the multi-stage compressor; a second decompressor for expanding the other portion of the boil-off gas, which has passed through the first self-heat exchanger after being compressed by the multi-stage compressor; and a second self-heat exchanger for heat-exchanging and cooling the portion of the boil-off gas, which has been compressed by the multi-stage compressor, by using, as a refrigerant, a fluid which has been expanded by the first decompressor.

Disclosed herein are a diagnostic method using laser induced breakdown spectrum analysis and a diagnostic device for performing the same. The diagnostic method may include projecting a pulsed laser to a suspicious specimen, obtaining first spectrum data on the light collected from the suspicious specimen, projecting the pulsed laser to a non-diseased specimen, obtaining second spectrum data on the light collected from the non-diseased specimen, and determining whether a disease is present in the suspicious specimen from a comparison value of the first spectrum data and the second spectrum data using an artificial neural network.

A BOG reliquefaction system includes: a compressor; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG not compressed by the compressor; a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger; and a combination of a first temperature sensor disposed upstream of a cold fluid channel of the heat exchanger and a fourth temperature sensor disposed downstream of a hot fluid channel of the heat exchanger, combination of a second temperature sensor disposed downstream of the cold fluid channel of the heat exchanger and a third temperature sensor disposed upstream of the hot fluid channel of the heat exchanger, or combination of a first pressure sensor disposed upstream of the hot fluid channel of the heat exchanger and a second pressure sensor disposed downstream of the hot fluid channel of the heat exchanger.

Disclosed is a BOG reliquefaction system. The BOG reliquefaction system includes: a compressor compressing BOG; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG not compressed by the compressor as a refrigerant; a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger; and a second oil filter disposed downstream of the pressure reducer, wherein the compressor includes at least one oil-lubrication type cylinder and the second oil filter is a cryogenic oil filter.

A refrigerant cycle pressure control system includes: a heat exchanger cooling boil-off gas received from a storage tank; a refrigerant cycle including a refrigerant circulation line, a refrigerant compressor, and an expander; an inventory tank storing the refrigerant to be charged to the refrigerant cycle; a refrigerant supply line connecting the inventory tank to an upstream side of the refrigerant compressor to replenish the refrigerant cycle with the refrigerant; a refrigerant discharge line connecting a downstream side of the refrigerant compressor to the inventory tank to discharge the refrigerant from the refrigerant cycle to the inventory tank; and a pressure regulation line branched off of the refrigerant discharge line. The refrigerant cycle is depressurized by discharging the refrigerant from the refrigerant cycle through the refrigerant discharge line or the pressure regulation line.

Disclosed herein are a method for diagnosing a disease of a body tissue by using LIBS (Laser-Induced Breakdown Spectroscopy) comprising: preparing a laser device including: a laser projection module, outputting the laser to a suspicious region of the body tissue, a light receiving module, receiving a plurality of light, a spectrum measurement module, and a guide unit; and projecting the laser to generate plasma by inducing tissue ablation in the suspicious region; wherein the laser projected to the suspicious region has a target area, and wherein the target area has smaller size than the suspicious region such that the target area is located inside the suspicious region.

A ship comprises an engine; a first self-heat exchanger which heat-exchanges boil-off gas discharged from a storage tank; a multi-stage compressor which compresses, in multi-stages, the boil-off gas that passed through the first self-heat exchanger after being discharged from the storage tank; a first decompressing device which expands one portion of the boil-off gas compressed by the multi-stage compressor; a second self-heat exchanger which heat-exchanges the other portion of the boil-off gas compressed by the multi-stage compressor, with the boil-off gas expanded by the first decompressing device; and a second decompressing device which expands the boil-off gas pre-cooled by the second self-heat exchanger and cooled by the first self-heat exchanger, wherein the first self-heat exchanger uses the boil-off gas discharged from the storage tank as a refrigerant for cooling the boil-off gas that passed through the second self-heat exchanger after being compressed by the multi-stage compressor.

An apparatus for reliquefaction of boil-off gas for a vessel, comprises: a compression unit for compressing the boil-off gas discharged from the storage tank; and a heat exchanger for heat-exchanging the compressed boil-off gas compressed by the compression unit with the boil-off gas discharged from the storage tank; a first expansion means for dividing the boil-off gas passing through the heat exchanger into at least two flows including a first flow and a second flow, and expanding the divided first flow; a first intercooler for cooling the second flow remaining after the division of the first flow by using the first flow expanded by the expansion means as a refrigerant; and a receiver for receiving a second flow having passed through the first intercooler, in which a downstream pressure of the compression unit is controlled by a flow discharged from the receiver.

A ship including a storage tank for storing a liquefied gas includes: a boil-off gas (BOG) heat exchanger installed on a downstream of a storage tank and heat-exchanges a compressed BOG (a first fluid) by a BOG discharged from the storage tank as a refrigerant, to cool the BOG; a compressor installed on a downstream of the BOG heat exchanger and compresses a part of the BOG discharged from the storage tank; an extra compressor installed on a downstream of the BOG heat exchanger and in parallel with the compressor and compresses the other part of the BOG discharged from the storage tank; a refrigerant heat exchanger which additionally cools the first fluid cooled by the BOG heat exchanger; and a refrigerant decompressing device which expands a second fluid sent to the refrigerant heat exchanger, and then sends the second fluid back to the refrigerant heat exchanger.

The invention relates to a system for generating mechanical energy, comprising at least: a compressor; an expander; a heat exchanger; said system having a motor operative mode in which said system additionally comprises: means for the intake of pressurised liquid nitrogen in a liquid nitrogen intake inlet of said exchanger, means for the intake of air or gaseous nitrogen in an air or gaseous nitrogen intake inlet of said exchanger, means for discharging vaporised nitrogen at a vaporised nitrogen outlet of said exchanger, and means for discharging air or cooled nitrogen at another outlet of said exchanger for air or cooled gaseous nitrogen; means for the intake of said vaporised nitrogen into the interior of said expander in order to expand same; means for the intake of the air or cooled gaseous nitrogen into said compressor so as to produce compressed air or gaseous nitrogen therein.